The primary topics include the prognostic significance of TILs in melanoma, breast cancer, colorectal cancer, and head and neck squamous cell carcinoma; the role of TILs in predicting the efficacy of neoadjuvant chemotherapy; the relationship between TILs and PD-L1; TIL assessment; TIL-related biomarkers; TILs in the TME; and tertiary lymphoid structures. This evidence concerns the gene CD274 and breast carcinoma.