Notably, the expression of C-C motif chemokine receptor 5 (CCR5) has been found to increase in glioma cells and mesenchymal stem cells, correlating with poor prognosis in patients (Kouno et al., 2004; Wang et al., 2016; Laudati et al., 2017; Kranjc et al., 2019; Novak et al., 2020). Here, CCR5 is linked to central nervous system cancer.