In addition, nucleotidemetabolism has long been recognized toprovide multiple pathways for the development of new anticancer treatments.55 Recently, it has emerged that HGPRT is upregulatedin malignant tumors and localized to the surface in some cancer cells,56 this likely due to the increased rate of DNAproduction compared to normally replicating human cells. The gene discussed is HPRT1; the disease is cancer.