Although the current understanding of the clinical response of ICI therapy indicates that there cannot be a single predictive biomarker, several factors have been identified as the core determinants of the efficacy of ICIs, such as tumor mutation burden (TMB) and particular mutational signature, the number of tumor-infiltrating lymphocytes (TILs), PD-L1 expression, immunosuppressive microenvironment, and MMR deficiency (MMRd) [106]. The gene discussed is CD274; the disease is neoplasm.