Although described more than a decade ago, the mechanism by which the JAK2 46/1 haplotype increases the risk of developing JAK2-mutated myeloproliferative neoplasms (MPN) remains unexplained. Inflammation and immunity are linked to MPN development and thus could be relevant to the mechanism by which 46/1 mediates its effect. Here, we show that PD-L1 expression is elevated in 46/1 haplotype both in healthy carriers and CD34+ cells from MPN patients. Using circular chromosome conformation …