Potentially targetable cytokine circuits in MPNs. In the BM environment of MPNs and CH, inflammatory cytokines generated by mutant cells or induced by infection/inflammation influence the self-renewal and competitive fitness of both MPN SCs and HSCs (represented by arrows in figure). Differential responses of MPN SCs and HSCs to certain cytokines present potential strategies of reversing the competitive differential between MPN and normal cells to rebalance the MPN ecosystem.