This study (NCT04180215), which began in 2019, is exploring treatment with HB-201, alternating sequences of HB-202 and HB-201, and combinations with a PD-1 inhibitor in patients with previously treated advanced or metastatic HPV16+ HNSCC or other cancers (Figure 2) (3, 42). The gene discussed is PDCD1; the disease is head and neck squamous cell carcinoma.