Purine and thiopurine metabolism. NT5C2 dephosphorylates endogenous and thiopurine-generated 6-hydroxypurine monophosphates before they are exported out of the cell. AICAR, 5-aminoimidazole-4-carboxamide ribonucleotide; dGTP, deoxyguanosine triphosphate; GMPS, guanosine monophosphate synthase; HGPRT, hypoxanthine-guanine phosphoribosyltransferase; IMPDH, inosine monophosphate dehydrogenase; Me6-MP, methyl 6-MP; Me6-TG, methyl 6-thioguanine; MeTIMP, methyl thioinosine monophosphate; NUDT15, Nudix hydrolase 15; PRPP, phosphoribosyl pyrophosphate; TPMT, thiopurine methyltransferase; XO, xanthine oxidase.