To determine the clinical relevance of the CD38+CD39+CD4+ T-cell signature identified in our studies in cancer patients, we used the top 17 upregulated genes identified in the CD38+CD39+CD4+ T effector_Gzmk cells from CITE-seq RNA data and performed gene set variation analysis of the entire TCGA dataset and generated a cytotoxic CD4 T-cell score for each patient. Here, CD38 is linked to cancer.