It has been described that the different members of the kinase family (JAK, JAK1, JAK2, JAK3, TYK2) can be constitutively activated in many hematopoietic malignancies, as well as in numerous types of cancer [38], such as bladder, colon, and cervical cancers and medulloblastoma [39], as well as leukemias [40] and lymphomas [41]. Here, JAK2 is linked to cancer.