ERBB2 and breast cancer: For contemporary breast cancer actionability, PIK3CA mutation is a biomarker for the FDA-approved PI3Kα inhibitor alpelisib, AKT1 mutation is indicated for agents such as capivasertib (AZD5363) and ipatasertib, and ERBB2 mutation for tyrosine kinase inhibitor neratinib [23,24,25,26,27].