FOXO3 is a key protein that controls the transcription of a number of genes crucial for regulating cell cycle control [11], DNA damage and stress responses [12–15], aging and longevity [12, 16], cellular apoptosis [12, 17–19], and suppression of cancer [20–23] in animal and human cells; gene knockout findings reveal FOXO3′s additional functions in tumor suppression [24] and the maintenance of the hematopoietic stem cell pool [25]. This evidence concerns the gene FOXO3 and cancer.