More importantly, we observed that the CHST15 mutation might induce HEL cell differentiation toward myeloid, monocytic and megakaryocytic lineages, which mimicked the bone marrow morphologic characterization ofPMF or ET, showing an enhancing effect of CHST15 mutation on MPN development (Fig. 7). The gene discussed is CHST15; the disease is myeloproliferative neoplasm.