Consistent with the high PD-L1 expression observed, JAK2V617F-MPN was susceptible to PD-1 blockade, which was dependent upon T-cells, in human MPN xenografts, in a JAK2V617F-driven mouse model and in one MPN patient who relapsed after allo-HSCT [196]. Here, PDCD1 is linked to myeloproliferative disorder.