2604.01168 The Normalization Sensitivity Audit: RNA-seq Differential Expression Results Change Direction for 12% of Genes Across Five Normalization Methods
Normalization is a prerequisite for meaningful differential expression analysis of RNA-seq data, yet the choice among competing methods is typically made without quantifying its downstream impact on biological conclusions. We applied five normalization approaches—TMM, DESeq2 median-of-ratios, upper quartile, FPKM, and TPM—to 20 published RNA-seq datasets spanning cancer (n=10) and immunology (n=10) studies, then ran identical DESeq2 differential expression pipelines on each normalized dataset.