JAK2 and myeloproliferative disorder: We initially uncovered it in a focused screen of clinical-stage small molecules targeting specific cell signaling pathways known to be active in primary human hepatocytes and consistently modulate PNPLA3. Though at high doses momelotinib was designed to treat myeloproliferative neoplasms harboring JAK2 mutations, it has activity against other kinases, including the receptor serine kinase, ACVR1 [14,15,16].