Raw-count embeddings improve single-cell foundation models

Journal: bioRxiv
Published Date:

Abstract

Single-cell transformer foundation models have grown to hundreds of millions of parameters, yet the preprocessing choices that underlie them, including gene ranking and library-size normalisation, have not been systematically benchmarked. Testing seven strategies, we find these elaborations are largely unnecessary: non-normalised, log-transformed counts give the best performance, and gene order barely matters, with even random ordering outperforming sophisticated rank-based schemes. The resulting model, Gene Intelligence, projects log1p-transformed raw counts directly onto each token embedding and jointly predicts masked tokens and counts, using no normalisation, positional encoding, or read-depth tokens. Despite this simplicity, it achieves state-of-the-art performance in the tested gene-level tasks and in doublet detection, and matches large current foundation models on cell-classification tasks while using 10- to 200-fold fewer parameters.

Authors

  • Schlede
  • S.; Muruganandan
  • T. P.; Gojjam Kantharaju
  • S.; Kisis
  • I.; Boecker
  • M.; Kim Alves Carpinteiro
  • M.; Schmitz
  • A.; Buchwald
  • L. M.; Sakthivelu
  • V.; Gülcüler Balta
  • G. S.; Anstötz
  • M.; Rueger
  • M. A.; Thomas
  • R. K.; Beleggia
  • F.

Categories