PREP and neoplasm: There were three enzymes identified in the coexpression networks: (i) the protein encoded by protein kinase, cAMP-dependent, catalytic, beta (PRKACB) is a protein kinase; (ii) the protein product from prolyl endopeptidase (PREP) is a protease; and (iii) the protein encoded by HIV-1 Tat interactive protein 2 (HTATIP2) is an oxidoreductase required for tumor suppression.