CD274 and skin squamous cell carcinoma: According to a recent report of the CARSKIN phase II trial involving patients with unresectable cSCC treated with pembrolizumab, the overall RR at 15 weeks for the 42 patients with PD-L1+ tumors at baseline (55%) was significantly higher than for the 12 patients (17%) with PD-L1- status (p-value = 0.02).