The information so far available suggests that PD-L1 could represent a useful prognostic marker for risk stratification of thyroid cancer patients, and that anti-PD-1/PD-L1 directed therapies could be a valid option for patients affected by the most aggressive thyroid cancers, such as PDTC and ATC, unresponsive to the currently available therapies. The gene discussed is PDCD1; the disease is thyroid cancer.