CD274 and non-small cell lung carcinoma: Initially approved by the FDA in 2016, pembrolizumab was sanctioned for use in patients with PD-L1-expressing metastatic NSCLC.318 By 2020, its application was extended to include treatment for patients with unresectable or MSI-H mCRC who had not previously received systemic treatment for advanced disease.319 A multitude of clinical trials, both completed and ongoing, have been conducted to assess the impact of pembrolizumab on advanced CRC.