Additionally, analysis of The Cancer Genome Atlas (TCGA) database (34, 35) further indicated that patients with high IL9 expression showed a trend for better overall survival, although not statistically significant, compared with those with low IL9 expression in tumor tissues with high CD8+ infiltration in human melanoma (skin cutaneous melanoma), colon cancer, and breast cancer (Supplemental Figure 4A). This evidence concerns the gene CD8A and breast cancer.