FOXO3 and cancer: To investigate the role of mitochondrial vs. nuclear FoxO3A in cancer cell response to chemotherapeutic agents, HCT116-FoxO3A−/− cells were transfected with FLAG-tagged vectors encoding for FoxO3A-wt, FoxO3A-S12A/S30A or FoxO3A-Δ242-271 and then cultured in the absence or presence of irinotecan (CPT-11), cisplatin (CDDP), 5-fluorouracil (5-FU) or etoposide (VP-13).