The JAK2 mutation JAKV617F, found in most non-CML MPN (myeloproliferative neoplasia), facilitates JAK2 interaction with and phosphorylation of PRMT5, which attenuates methylase activity by preventing interaction with MEP50 [115]. The gene discussed is PRMT5; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.