Our data demonstrated the efficacy of BYL719 on reversing EGFR-TKI resistance, not only in PIK3CA mutated HCC-827-PIK3CA-M and PC-9-PIK3CA-M cells, but also in PI3K/AKT activated cells due to ErbB2 amplification (H1975) or PTEN deletion (H1650). The gene discussed is ERBB2; the disease is hepatocellular carcinoma.