PIK3CA and chronic myelogenous leukemia, BCR-ABL1 positive: TKI-mediated nuclear translocation of FOXO3 leads to cell cycle arrest [23] and further induces drug resistance of CML cells via regulation of the multidrug resistance gene 1 (MDR1) and the phosphatidylinositol-4,5-bisphosphate-3-kinase catalytic subunit alpha (PIK3CA) [4, 5].