ERBB2 and breast cancer: More recently, in 2024, inavolisib (GDC-0077)—another selective orthosteric PI3Kα inhibitor that additionally promotes mutant PI3Kα degradation [185]—emerged as an additional treatment option for HR-positive, HER2-negative, PIK3CA-mutant breast cancer, in combination with palbociclib, a CDK4/6 inhibitor, and fulvestrant [154,183].