CD274 and squamous cell carcinoma: The KeyNote 024 study was the first to demonstrate the benefit of pembrolizumab at a fixed dose of 200 mg every 3 weeks versus platinum-based CT, in a population selected using PD-L1 expression in tumor cells (patients who presented PD-L1 expression >50% were included), excluding patients with activating mutations in EGFR or translocations in ALK, rather than by histology (adenocarcinoma and squamous carcinoma).