Furthermore, we investigated the correlation between IGFBP5 expression and PD-L1, CXCR4 expression in glioma using the CGGA and TCGA databases and the results showed IGFBP5 expression was positively correlated with PD-L1 and CXCR4 expression (Figure 11C, D). The gene discussed is CXCR4; the disease is glioma.