Secondly, differences in the immune microenvironment across lung cancer pathological subtypes significantly impact ICIs response patterns and prognosis: small cell carcinoma exhibits an “immune desert” phenotype (characterized by insufficient CD8+ T-cell infiltration and Treg enrichment), whereas tertiary lymphoid structures within lymph node metastases in adenocarcinoma may potentiate anti-tumor immunity (37, 38). The gene discussed is CD8A; the disease is small cell carcinoma.