RARA and acute promyelocytic leukemia: Importantly, this work addresses a different question than the work of Guibal et al., which defined the immunophenotype of a committed myeloid progenitor (cKit+CD34+FcγRII/III+Ly6gint) as the leukemia-initiating cell in the hMRP8-PML-RARA transgenic mouse model of APL.