The PPIA, H2AFZ, and HPRT1 genes have been proven to be the most stable reference genes in mouse oocytes and preimplantation-stage embryos under different culture conditions [20], while HPRT1 and RPL13A have been demonstrated to be the most stable reference genes in glioma stem cells (GSCs) [21]. The gene discussed is HPRT1; the disease is glioma.