In particular, in a subset of patients the PML-RARA fusion is not detected, but other rearrangements are identified that involve RARB and RARG, two distinct isoforms of RARA, that cause a pathological phenotype that resembles APL (Marinelli et al., 2007; Osumi et al., 2018). This evidence concerns the gene RARB and acute promyelocytic leukemia.