CD44 and central nervous system cancer: Because CD44 expression level is positively correlated with M2-type macrophage infiltration (Figure 5B), we verified the infiltrating M2 TAMs among different CD44+ cell infiltration levels by IHC (Figure 10A) and found that the more CD44+ cells are detected, the more M2 TAMs infiltrate, which is consistent with the correlation of CD44 with CD163 in the TCGA and CGGA glioma datasets (Figure 10B).