In MPN patients negative for JAK2, CALR, and MPL (triple-negative, TN), mutations in LNK, TET2, DNMT3A, IDH1/2, CBL, and ASXL1 genes but also atypical mutation in MPL (S204P) have been identified (83, 85). The gene discussed is CALR; the disease is myeloproliferative neoplasm.