To investigate CD4 T cell exhaustion, because virtually all CD4 tumor-infiltrating lymphocytes (TILs) do not express CD45RA, we assessed IC expression in memory conventional FOXP3- CD4 T cells (CD4 Tconvs; Supplemental Figure 1A; supplemental material available online with this article; https://doi.org/10.1172/jci.insight.142513DS1) from TILs of patients with head and neck cancer, cervical cancer, and ovarian cancer (OC). Here, CD4 is linked to head and neck cancer.