Although members of the FOXO subfamily have similar sequences (resulting in function redundancy) [9], null mutations in FOXO1, FOXO3, and FOXO4 yield specific phenotypes in mice and show that each FOXO gene has unique physiological effects and a distinct function [10]. FOXO3 is located at a mammalian and human cancer-associated site [t (6;11) (q21; q23)] and is highly similar to other FOXO gene family members, according to cDNA library screening [11]. This evidence concerns the gene FOXO3 and cancer.