It is possible that HNSCC patients whose T cells display lower Ca2+ fluxing abilities in vitro had a higher exposure to circulating PD-L1 (either soluble or via tumor-derived exosomes) in vivo, and they will ultimately benefit the most from αPD-L1 and αPD-1 blockade. The gene discussed is CD274; the disease is head and neck squamous cell carcinoma.