Genes particularly increased at protein level in granulocytes of JAK2 positive MPNs were: ANXA5, KRT10, LGALS1, splicing factor 3b, subunit 2 (SF3B2) in PMF; chitinase 1 (CHIT1), HSPA1A, PSME2 in ET; and chaperonin containing TCP1, subunit 2 (CCT2) in PV; as well as in JAK2 negative MPN subjects: NDRG1, GDI2, glucose-6-phosphate isomerase (GPI), and PTPN6 (Table 4). The gene discussed is HSPA1A; the disease is essential thrombocythemia.