In another phase I study (NCT02318394), the antibody MEDI0562 showed promising therapeutic efficacy through increased proliferation of effector T cells (increased Ki67+ CD4+ and CD8+ memory T cell in the periphery) and decreased intratumoral OX40+ CD4+CD25+Foxp3+high Treg cells in patients with advanced solid tumours, including HNSCC [498]. Here, CD4 is linked to head and neck squamous cell carcinoma.