PIK3CA-mutant cancer cell lines including cervical cancer cell lines (Caski, C33A, and ME-180), breast cancer cell lines (T47D and MCF7), and A2780 ovarian cancer cell line, and wild-type HeLa and SiHa cervical cancer cell lines were treated with BKM120, a pan-isoform PI3K inhibitor that is a leading drug among PI3K inhibitors currently undergoing clinical trials, and hydroxychloroquine (HCQ), an autophagy inhibitor, alone or in combination. This evidence concerns the gene PIK3CA and breast cancer.