For example, Siglec-15 was positively associated with CD8+ T cells in adrenocortical carcinoma but negatively associated with CD8+ T cells in BRCA basal breast cancer.19 The correlation between the composition of immune cells and Siglec-15 in ESCC remains unclear, which warrants further investigation. This evidence concerns the gene CD8A and esophageal squamous cell carcinoma.