HLA-C and neoplasm: Altogether, reduced CD8+ T-cell infiltration—caused by PCSK9-mediated deficiency of the tumor antigen peptide–MHC that could be targets for cytotoxic T-cell recognition—might be one of the reasons why patients with PCSK9lo tumor tissue were more likely to benefit from ICIs compared with those with PCSK9hi tumor under advanced NSCLC treatment.