This increase in p300 proteins in CHMP5-KD T-ALL cells is likely due to its impaired interaction with BRD4 as targeted degradation of BRD4 using the PROTAC degrader MZ149 also resulted in increased p300 proteins in CHMP5-sufficient cells (Supplementary Fig. 5c, d). Here, BRD4 is linked to acute lymphoblastic leukemia.