saberhq.com / sidechain
Virtual Cell Challenge · 2026

Sidechain.

Predicting how a cell's transcriptome shifts when a gene is silenced — a solo entry to the Virtual Cell Challenge 2026, built in the open.

Chasing top 10% for the fun of it ;)
top 10%
Best
0.2226
SER-29abefhkrswx · #221 of 1638
Latest
0.2226 +0.0351
SER-29abefhkrswx · #221 of 1638
Gap to top 100 · top 20
0.0505·0.0891
from #211 of 1622 · Oct 21
To final test set · deadline
Oct 22·Nov 5

Every submission, as Arc scored it. The live board shows only a team's latest entry, so the rank is the one each entry held when it was scored. An entry's model card is the sentence beside it on the board, and the models page says what each model tried and what its name means.

Overall score · 0 = the context mean, 1 = a biological replicate
00.3
SER-29abefhkrswx 0.2226

Details on this and every Sidechain model: saberhq.com/sidechain/models/

SER-28abefhkrswx 0.1875

Details on this and every Sidechain model: saberhq.com/sidechain/models/

SER-27abefhkrswx 0.1875

Details on this and every Sidechain model: saberhq.com/sidechain/models/

SER-21aefhkrswx 0.1757

Details on this and every Sidechain model: saberhq.com/sidechain/models/

SER-19aefhkrsw 0.1684

Details on this and every Sidechain model: saberhq.com/sidechain/models/

SER-17aefhkrsw 0.1657

Details on this and every Sidechain model: saberhq.com/sidechain/models/

SER-14aefksw 0.1626

Tests whether adaptive shrinkage improves predictions: each borrowed gene change is shrunk by how believable it is against all of that knockdown's genes together, instead of dropping changes below a fixed noise threshold. Details on this and every Sidechain model: saberhq.com/sidechain/models/

SER-13aefknw 0.1360

Tests whether predictions improve when each knockdown's summed profile carries the same strength as its individual cells, instead of a stronger one. Details on this and every Sidechain model: saberhq.com/sidechain/models/

SER-12aefkw 0.1438

Tests whether shrinking each borrowed gene change by its own measurement noise, so that a change no larger than its noise is dropped, improves predictions. Details on this and every Sidechain model: saberhq.com/sidechain/models/

SER-11abefknw 0.1360

Tests whether a knockdown's predicted response improves when it is blended with the responses of its nearest genes in the STRING protein-interaction network, on top of the pooled control profile the scorer uses. Details on this and every Sidechain model: saberhq.com/sidechain/models/

SER-10abefnw 0.1353

Tests whether predictions improve when each knockdown's summed profile is built on the control profile the scorer itself uses, pooled across control cells so deeper cells count more, instead of an average over cells. Details on this and every Sidechain model: saberhq.com/sidechain/models/

SER-9abefkn 0.1144

Tests whether a knockdown's predicted response improves when it is blended with the responses of its nearest genes in the STRING protein-interaction network. Details on this and every Sidechain model: saberhq.com/sidechain/models/

SER-7abefn 0.1131

SER-7abefn = cross-line delta transfer, model 7 (a = amplified transfer, b = summed-profile strength set apart, e = emission dial at lambda 0.5, f = floored source weights, n = no shrinkage). Borrows each gene's knockdown response from K562, H1 and two genome-wide screens in colon and kidney lines, as SER-6aefn does; the emitted cells now carry that response at strength 1.5 in their summed profile and 1.35 cell by cell -- the one change from SER-6aefn. All models: saberhq.com/sidechain/models/

SER-6aefn 0.1091

SER-6aefn = cross-line delta transfer, model 6 (a = amplified transfer, e = emission dial at lambda 0.5, f = floored source weights, n = no shrinkage). Borrows each gene's knockdown response from K562, H1 and two genome-wide screens in colon and kidney lines, scales it to reference strength, and emits cells with half the Poisson spread instead of identical ones -- the one change from SER-4afn. All models: saberhq.com/sidechain/models/

SER-5acfnt 0.1075

SER-5acfnt = weights each source's vote by how well it actually predicts a new cell line, not by how confident it sounds. All models: saberhq.com/sidechain/models/

SER-4afn 0.1078

SER-4afn = cross-line delta transfer, model 4 (a = amplified transfer, f = floored source weights, n = no shrinkage). Borrows each gene's knockdown response from K562, H1 and two genome-wide screens in colon and kidney lines, and scales it up to reference strength, because those screens silenced their targets only partially. All models: saberhq.com/sidechain/models/

SER-3afn 0.1071

SER-3afn = cross-line delta transfer, model 3 (a = amplified transfer, f = floored source weights, n = no shrinkage). Borrows each gene's knockdown response from K562, H1 and two genome-wide screens in colon and kidney lines, and scales it up to reference strength, because those screens silenced their targets only partially. All models: saberhq.com/sidechain/models/

SER-3afgn 0.0992

SER-3afgn = cross-line delta transfer, model 3 (a = amplified transfer, f = floored source weights, g = abundance-ratio transfer exponent, n = no shrinkage). SER-3afn with one setting changed: instead of carrying each gene's fold change over unchanged, the borrowed effect is bent toward the new line's own resting abundance of that gene. All models: saberhq.com/sidechain/models/ (card written after the entry was scored)

SER-3fn 0.1034

SER-3fn = cross-line delta transfer, model 3 (f = floored source weights, n = no shrinkage). Borrows each gene's knockdown response from K562, H1 and two genome-wide screens in colon and kidney lines, trusts each source only as far as its cell counts justify, and re-anchors it on the new line's resting state. All models: saberhq.com/sidechain/models/

SER-3n 0.0963

SER-3n = cross-line delta transfer, model 3 (n = no shrinkage). The same four sources as SER-2, with the two genome-wide screens read in full — every gene they measured rather than the challenge panel alone — re-anchored on the new line's resting state. All models: saberhq.com/sidechain/models/ (card written after the entry was scored)

SER-2 0.0937

SER-2 = cross-line delta transfer, model 2 (named before the knob letters; shrinkage off, as in SER-1n). Borrows each gene's knockdown effect from K562, H1 and the challenge-panel slice of two genome-wide screens in colon and kidney lines — the first entry to cover all 300 targets — and re-anchors it on the new line's resting state. All models: saberhq.com/sidechain/models/ (card written after the entry was scored)

SER-1n 0.0822

SER-1 with the transferred log2FCs left unshrunk (no gene-wise positive-part shrinkage); minimum-variance cells. Probe: does shrinkage remove small true signals that cosine-PDS needs?

SER-1p 0.0730

Same transferred log2FCs as SER-1 (K562 genome-wide + H1, inverse-variance pooled, gene-wise shrinkage, alpha=1), emitted as independent Poisson cells at control depth instead of minimum-variance cells. Controlled experiment on emission dispersion.

SER-1 0.0788

Rung 1': per-gene log2FC pooled (inverse-variance) over K562 genome-wide + H1 2025 for the targets they cover, gene-wise positive-part shrinkage, re-anchored on each context's control profile; minimum-variance (even-spread) integer cells at control depth; 28 uncovered targets get the H1 mean shift.

Calibration runs · what this means →
SER-20aefhkrsw 0.1673

Details on this and every Sidechain model: saberhq.com/sidechain/models/

SER-18aefksvw 0.1612

Details on this and every Sidechain model: saberhq.com/sidechain/models/

SER-16aefhkrsw 0.1423

Details on this and every Sidechain model: saberhq.com/sidechain/models/

SER-15aefkrsw below zero · off this scale −0.0039

Details on this and every Sidechain model: saberhq.com/sidechain/models/

SER-8abefkn 0.1132

Tests whether a knockdown's predicted response improves when it is blended with the responses of the genes nearest to it in Tahoe-x1's gene embedding. Details on this and every Sidechain model: saberhq.com/sidechain/models/

PHE-2 below zero · off this scale −0.9807

PHE-2 = a neural network trained on two cancer cell lines, asked to predict each knockdown's cells directly from an unseen line's untouched controls. All models: saberhq.com/sidechain/models/