A positive correlation has been demonstrated with the infiltration of cancer-associated fibroblasts and myeloid-derived suppressor cells across several cancer types [10], with an immune risk score based on enrichment of 2 T helper cells, memory B cells and plasmacytoid dendritic cells in lower-grade glioma [113], with the infiltration of CD8+ T cells, monocytes [114, 115], exhausted T cells [114], CD4+ T cells, regulatory T cells, B lymphocytes, and natural killer cells [115] in hepatocellular carcinoma. The gene discussed is CD4; the disease is cancer.