EWSR1 and Ewing sarcoma: Notable examples include iCBP4 (derived from CCS1477), which selectively targets EP300/CBP in Group 3 MB, and the bromodomain inhibitor iP300w, which prevents P300/CBP-mediated histone acetylation, thereby disrupting EWS::FLI1-driven oncogenic signaling in Ewing sarcoma [202,203].