Myeloid cells derived IL-6 and IL-1b modulate the niche in leukemia (18, 38). IL-6 induces myeloid differentiation of MPPs in CML (38). IL-1b induces apoptosis in sympathetic nerve fibers resulting in a loss of MSCs and expansion of HSCs in MPD (18). The gene discussed is IL1B; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.