PIK3CA and breast cancer: Specifically, we quantified six hotspot CDMs (PIK3CA H1047R, PIK3CA E545K, KRAS G12D, KRAS G12V, HRAS G12D, and BRAF V600E) in 81 IDCs (approximately 20 samples for each of the four breast cancer subtypes), using the sensitive and quantitative ACB-PCR approach.