CD4 and neoplasm: In addition to CD8 T cells, CLU expression showed outstanding positive correlations with the other five immune cells, including DCs (r = 0.341, p = 2.03 × 10−14), B cells (r = 0.183, p = 5.56 × 10−5), neutrophils (r = 0.328, p = 2.37 × 10−13), CD4+ T cells (r = 0.342, p = 1.54 × 10−14), and macrophages (r = 0.401, p = 1.15 × 10−19), which determined a negative correlation (r = −0.341, p = 1.54 × 10−14) of CLU expression with tumor purity in LGG (Figure 4B).