To identify the mechanistic basis for the differential effects of TNF on MF vs. normal cells, we quantified TNF receptor expression in primitive (Supplemental Figure 3a) and mature (Supplemental Figure 3b) hematopoietic cells from human MF vs. normal BM and JAK2V617F+ vs. JAK2V617F− cells from MPN mice (Supplemental Figure 3c). Here, TNF is linked to myeloproliferative disorder.