NBTXR3, activated by RT in combination with anti-PD-1 therapy, recently entered a phase I clinical trial, including a cohort of patients with locoregionally recurrent (LRR)- or R/M-HNSCC who are resistant to anti-PD-1 therapy, with injectable lesions located in the head and neck area, lung, or liver (NCT03589339). Here, PDCD1 is linked to head and neck squamous cell carcinoma.