In clinic, the APL patient with PML-RARA/ARID1B-WASH4P exhibited sensitive to APL therapy, indicating ARID1B-WASH4P was not dominate in its pathogenesis, while the APL patient with TBC1D15-RAB21 received AML therapy plus ATRA and achieved CR, so whether TBC1D15-RAB21 was sensitive to APL therapy remained unknown. Here, RAB21 is linked to acute promyelocytic leukemia.