In these experiments, we found that the JAK2 inhibitors fedratinib (Figures 3 and S9) and ruxolitinib (Figures 3 and S10) suppressed IFN‐G‐ and TNF‐A‐induced upregulation of PD‐L1 in both JAK2V617F‐ and CALR‐mutated MPN cells. Here, TNF is linked to myeloproliferative disorder.