HMGA1 and acute lymphoblastic leukemia: Transgenic mice overexpressing Hmga1a develop T-cell acute lymphoblastic leukemia/lymphoma phenotype (T-ALL) [174]; the effect of Hmga1a overexpression on proliferation is exacerbated by the loss of the Cdkn2a tumor suppressor gene, that encodes, from alternative reading frames, the two cell cycle inhibitors p16INK4A and p14ARF (p19ARF in mice) [175].