For example, the effect of nutlins initially seemed to be limited to cells harboring wild type p53, subsequent research revealed that nutlin also exerted its anti-cancer activities in p53-negative and p53-mutant human tumor cells through different mechanisms including activation of E2F1 or p73 in different types of cancers including hematological malignancies [48,72,104,105]. This evidence concerns the gene E2F1 and cancer.