EP300 and synovial sarcoma: In other words, CBP/p300 dual inhibitors are a promising treatment for SMARCB1-deficient rhabdoid tumors (almost 100%), epithelioid sarcomas (nearly 100%), SMARCA4/SMARCA2-deficient non–small cell lung cancer (10%), ovarian small cell carcinoma (100%), and SS18–SSX fusion synovial sarcomas (100%; ref. 3).