CD8A and head and neck squamous cell carcinoma: Although LAG3 is another potential target of immunotherapy, a study on pan-cancer from the TCGA found that although the CD8 + T cell marker CD8a and LAG-3 are strongly coexpressed in most cancers, there are still three obvious exceptions: HPV + head and neck squamous cell carcinoma, RCC and glioblastoma (Panda et al. 2020).