IL2 and head and neck cancer: Combinations of checkpoint blockade with antibodies such as trastuzumab and cetuximab, or with long half-life IL-2, have been safely tested in patients with advanced HER2-positive gastric cancer (Chung et al., 2021), recurrent/metastatic head and neck cancer (Sacco et al., 2020), and other advanced solid tumors (Diab et al., 2020).