PIK3CA and ovarian cancer: At the molecular level, ovarian cancer is considered to be an extremely heterogeneous disease with somatic and germline mutations, in tumor suppressor genes and DNA repair genes, and oncogenes such as BRCA1, BRCA2, KRAS, BARD1, BRAF, PTEN, PIK3CA, BRIP1, MRE11A, MSH6, CHEK2, NBN, RAD50, PALB2, RAD51C, and TP53 have role in proliferation, invasion, and metastasis process of ovarian cancer cells [121].