PML and acute promyelocytic leukemia: The partner gene located in the breakpoint region on chromosome 15q22, originally named MYL, was a previously unknown gene later on renamed Promyelocytic Leukemia gene or PML. This gene was subsequently shown to be involved in the control of cell proliferation, apoptosis and senescence.21 The availability of in vitro (NB4 cell line) and in vivo (transgenic mouse) models harboring the PML-RARA fusion gene fostered investigation on APL leukemogenesis.