B Endogenous USP45 was immunoprecipitated (IP) from wild‐type (WT) and USP45 knockout (KO) KBM7 cells lines. The immunoprecipitates were resolved on a polyacrylamide gel and stained with Instant Blue. The gel was divided into the indicated sections, and proteins identified by mass spectrometry are detailed in Supplementary Table S1. The key proteins that we focus on in this study are indicated. 