JAK2 and myeloproliferative disorder: Bone marrow stroma-derived cytokines protect Janus-activated kinase 2-V617F (JAK2(V617F)) mutant cells from the effects of atiprimod, a strong JAK2 inhibitor.89 Such protection is associated with high levels of IL-6 and several other factors including fibroblast growth factor and chemokine C-X-C-motif ligand 10 (CXCL10), thus underscoring the importance of targeting the marrow niche in myeloproliferative neoplasms for therapeutic purposes.