CDKN2A and acute lymphoblastic leukemia: In addition, a previous study showed that MYCN overexpression rapidly led to acute myeloid leukaemia (AML) in mice.30 MYCN was able to induce pre‐B‐ALL/LBL directly from the progenitor B cells of mice in the absence of Ink4a and Arf. 31 In our experiments, MYCN promoted cell proliferation and inhibited apoptosis.