Research suggests that certain conventional biomarkers like PD-L1 expression and Tumor mutational burden (TMB) are not significantly associated with the success of immuno-combination chemotherapy in SCLC and have yet to be proven effective predictors (Paz-Ares et al. 2019; Reck et al. 2019; Antonia et al. 2016). The gene discussed is CD274; the disease is small cell lung carcinoma.