The rise of more flexible study designs helped in the assessment of the role of biomarkers, even in the small cohorts of phase 1 studies: in the case of pembrolizumab, for instance, data regarding PD-L1 expression and activity in 15 patients informed later phases, leading to the cut-off identification of PD-L1 > 50% in NSCLC in a relatively short time. Here, CD274 is linked to non-small cell lung carcinoma.