Nature Communications, Published online: 15 June 2026; doi:10.1038/s41467-026-74204-8 Small cell carcinoma of the ovary, hypercalcemic type, is a rare, aggressive cancer caused by SMARCA4 inactivation and features wild-type p53. Here, the authors suggest that loss of SMARCA4 alters chromatin and reprograms p300 binding, undermining p53’s transcriptional repression and promoting cancer growth.