CD8A and neoplasm: Therefore, this study comprehensively characterized Siglec-15 expression, highlighted their clinical significance, elucidated the spatial distribution relationship between tumor-infiltrating immune cells (TIICs) and Siglec-15, and provided new insights into anti-Siglec-15 immunotherapy through immunophenotyping based on Siglec-15 expression and CD8A expression/CD8+ T cells infiltration.