PIK3CA gene mutations were found in 30%–40% of OCCC patients, and PIK3CA gene mutation was also found in endometriosis lesions of these patients, indicating that the PI3K-mediated pathway played an important role in the tumorigenesis of OCCC and that PIK3CA gene mutation is one of the early events in endometriosis-related OCCC (Kuo et al., 2009; Yamamoto et al., 2011; Murakami et al., 2021). The gene discussed is PIK3CA; the disease is endometriosis.