A. HeLa cells were transfected with either EV-FLAG or increasing concentrations (2μg, 6μg) of PLK1-FLAG and the expression of FOXO1, FOXO3, BIM, p27, PLK1, P-NPM1 Ser4 & NPM1 was monitored by western blot. PLK1 induces a decrease in BIM (24h) and p27 (18h and 24h), well known FOXO targets; B. HeLa cells were transfected with EV-FLAG or PLK1-FLAG. Expression of p27 was evaluated. The results show that PLK1 decreases p27 levels; β-Actin was used as a loading control; PLK1 activity is determined by measuring the phosphorylation of NPM at Ser4 (site known to be phosphorylated by PLK1)42; SC = anti-FOXO3 antibody from Santa Cruz Biotechnology;