CCL5 and small cell lung carcinoma: In this study, aiming to discover molecular markers that play a key role in prognosis and the efficacy of immunotherapy for SCLC patients, we used ESTIMATE algorithm to calculate immune scores in SCLC samples from 159 cases of SCLC from two published cohorts and used Cox regression analysis to search for prognostic immune markers, leading to the identification of C-C Motif Chemokine Ligand 5 (CCL5).