Expression of activation markers, indicative of in situ stimulation and proliferation, and tissue residency are compatible with the accumulation of tumor Ag–specific CD4 T cells at the tumor site where they are found at higher frequencies than in the periphery (5) and could imply that, like exhausted CD8 TILs, exhausted CD4 TILs encompass Ag-specific T cells. The gene discussed is CD4; the disease is neoplasm.