Our results revealed a new mechanism by which the Hippo–YAP pathway in DLBCL is inactivated by KIAA1429/YTHDF2-coupled epitranscriptional repression of CHST11, highlighting the potential of KIAA1429 as a novel predictive biomarker and therapeutic target for DLBCL progression. Here, YAP1 is linked to diffuse large B-cell lymphoma.