CD274 and thyroid cancer: The development of neutralizing monoclonal antibodies to PD-1/PD-L1 (along with other critical immune checkpoints, such as CTLA-4) has led to improved patient survival in many cancer types.15,16 Initial reports of the use of anti-PD-1 in thyroid cancer (pembrolizumab in metastatic DTC, spartalizumab in ATC) show promise, although response rates are variable.17,18