Although a laboratory assessment offers some guidance as to an APL diagnosis and prognosis through white blood cell count, bone marrow cell morphology, and t (15:17) chromosomal translocation and PML-RARα fusion gene assays, early and direct methods to indicate the treatment effects of ATRA on APL remain lacking, especially molecular biological methods that are effective, quick and simple. Here, RARA is linked to acute promyelocytic leukemia.