JAK2 and myeloproliferative disorder: This review summarizes current understanding of how inflammation drives MPN pathogenesis, from clonal initiation to progression and symptom burden, and explores how emerging therapies modulate the inflammatory microenvironment.<h4>Recent findings</h4>Evidence from human genetics, epidemiology, and experimental models shows that chronic inflammatory stress promotes the expansion of JAK2- and other MPN-associated clones.