JAK2 and myeloproliferative neoplasm: However, although all the other altered processes observed in mutant worms (cellular metabolism, extracellular matrix, epigenetics, and Wnt, Hedgehog, and Notch signaling) are known to regulate and guide hematopoietic development, they have not previously been described as a direct consequence of mutant calreticulin independently of its action via JAK2 or MPL in MPN patients.