In concomitantly analyzed gene expression in CD34+ cells of MPNs, the following genes showed highly significant (p<0.01) and increased expression in JAK2 positive MPN subjects: APEX1, chromobox homolog 1 (CBX1), FCN1, TPM3, dihydrolipoamide S-succinyltransferase (DLST), GLRX, malic enzyme 2, NAD(+)-dependent, mitochondrial (ME2), and RAB10. The following genes have increased expression in JAK2 negative MPN subjects: FNBP1, GNAI2 and proliferation-associated 2G4 (PA2G4, Table 4). The gene discussed is APEX1; the disease is myeloproliferative disorder.