SIGLEC9 and glioma: As shown in Figure 4A, the SIGLEC9 expression was mostly positively correlated with myeloid-derived suppressor cell (MDSC) infiltration (Cor = 0.84, P < 2.2e−16), effector memory CD8+ T cell infiltration (Cor = 0.71, P < 2.2e−16), T follicular helper cell infiltration (Cor = 0.67, P < 2.2e−16), regulatory T cell infiltration (Cor = 0.63, P < 2.2e−16), mast cell infiltration (Cor = 0.58, P < 2.2e−16), and neutrophil infiltration (Cor = 0.27, P < 9.6e−13) in gliomas.