JAK2 (Janus kinase 2; located on chromosome 9p24), MPL (myeloproliferative leukemia virus oncogene; located on chromosome 1p34), and CALR (calreticulin; located on chromosome 19p13.2) are specific somatic driver mutations that have been described in the major part of BCR-ABL–negative neoplasms [6,8]. This evidence concerns the gene JAK2 and neoplasm.