SCLCs were found to have relatively colder immune profiles than lung adenocarcinomas and squamous cell carcinomas, characterized by lower expression of <i>HLA</i> genes, immune cell, and immune checkpoint genes, except the <i>LAG3</i> gene.<h4>Conclusions</h4>Clinical-grade SCLC RNA expression profiling has value for SCLC subtyping, design of clinical trials, and identification of patients for trials and potential targeted therapy. The gene discussed is LAG3; the disease is small cell lung carcinoma.