Additional pathogenic mutations, including KRAS p.(Ala59Thr), PIK3CA p.(Thr1025Ala), and PIK3R2 p.(Lys564Glu), were identified in that particular stage-3 specimen, suggesting that the tumor is refractory to the anti-HER2 treatment [33,34,35]. The gene discussed is PIK3CA; the disease is neoplasm.