AL results from clonal proliferation of myeloid and lymphoid progenitor cells.268 Acute promyelocytic leukemia (APL, the most curable AML subtype) has been labeled a paradigm for targeted differentiation therapy.269 APL results from a t(15;17)(q22;q21) translocation that fuses RARA (a gene encoding retinoic acid receptor α, RARα) on 17q21 to PML (a gene encoding promyelocytic leukemia protein, PML) on 15q22. This evidence concerns the gene PML and acute myeloid leukemia.