For example, two clinical trials of checkpoint inhibitor drugs for Non-Small Cell Lung Cancer: KEYNOTE-024 (Keytruda) (Reck et al. 2016 and https://clinicaltrials.gov/ct2/show/NCT02142738) by Merck and CheckMate-026 (Opdivo) (Carbone et al. 2017 and https://clinicaltrials.gov/ct2/show/NCT02041533) by Bristol-Myers used IHC to determine the levels of PD-L1 biomarker. This evidence concerns the gene CD274 and non-small cell lung carcinoma.