A review on the selection of normalizers for RT-qPCR cancer studies recommended that a combination of PPIA and ACTB, HPRT1 (hypoxanthine phosphoribosyltransferase 1), TBP (TATA-binding protein), or GAPDH, or an appropriate combination of three of these genes, should be employed [72]. The gene discussed is PPIA; the disease is cancer.