PIK3CA and breast cancer: Younger patients (≤35 years) with breast cancer had more mutations in EZH2 but fewer mutations in PIK3CA and MAP3K1 (P<0.05, Figure 2E) and more CN amplifications in 12 genes including PRKDC, RUNX1T1, IGF1R, IRS2, NTRK3, CARD11, FGFR3, LATS1, MEN1, PIK3CG, PPP6C, and TRRAP (P<0.05, Figure 2F).