Mechanisms promoting immune escape of MPN and transformation to acute myeloid leukemia include increased PD-L1 expression (5), immune-checkpoint ligand upregulation (6), reduced IL-15 production (7), reduced MHC and TRAIL-receptor expression (8), increased IL-1β production (9) and leukemia-derived lactic acid release (10). Here, IL15 is linked to myeloproliferative disorder.