DPP4 and central nervous system cancer: Busek et al. (2012) indicated that DPP4, which is highly expressed in gliomas with a high risk score, inhibits glioma cell growth independent of its enzymatic activity. Another study showed that DPP4 was related to the stemness of glioma stem cells (Sakamoto et al., 2019). Sohn et al. (2013) demonstrated that CISD1 that was highly expressed in human epithelial breast cancer cells suppressing CISD1 expression significantly inhibited cell proliferation and tumor growth. ARK1C2 was found to positively regulate proliferation in cancer cells (Ji et al., 2004).