CTLA4 and head and neck cancer: It is also being investigated in combination with immunotherapy in a phase 1 study for solid tumors (NCT03447314), in combination with pembrolizumab/5‐fluorouracil/platinum in a phase II/III study of head and neck cancer (NCT04428333; INDUCE‐4), in combination with pembrolizumab in a phase II/III study of PD‐1 positive head and neck cancer (NCT04128696; INDUCE‐3), and a phase I/II study of solid tumors in combination with tremelimumab (anti‐CTLA‐4 antibody) or standard of care (paclitaxel, docetaxel, or cetuximab) (NCT03693612).