Importantly, PCR assays have been developed for three AML phenotypes: (i) acute promyelocytic leukemia (APL) (fusion gene PML::RARA); (ii) patients with NPM1 and CBF–AML (RUNX1::RUNX1T1 and CBFB::MYH11); and (iii) AML with fusion genes BCR::ABL1, KMT2::MLLT3, and DEK::NUP214 [18,25]. The gene discussed is RARA; the disease is acute myeloid leukemia.