CD274 and small cell lung carcinoma: Herein, we aim to illustrate the genomic alteration patterns of homologous recombination repair (HRR)‐related genes in a Chinese SCLC cohort and further analyze the relationship among HRR gene mutations and known biomarkers of immune checkpoint inhibitor (ICI) response, including tumor mutation burden (TMB) and programmed cell death‐ligand 1 (PD‐L1) expression.