JAK2 and familial thrombocytosis: Other JAK2 mutations have been highlighted in hereditary thrombocytosis with sometimes the same residue affected than in sporadic MPN cases but with a different amino acid changes, such as JAK2 V617I, or on different residue located in both the pseudokinase (JAK2 H608N, JAK2 R564Q, JAK2 S755R) and the kinase domain of the protein (JAK2 R938Q and JAK2 R867Q) (38–41).