CD4 and neoplasm: Immunofluorescence-based staining of T-cell subsets in the ilea and tumor beds revealed an inverse correlation between CD3+ and CD4+ T lymphocytes within the ileal epithelium (EP) or lamina propria (LP), and CD8+ tumor-infiltrating lymphocytes (TILs) in the invasive margins of the resected pCC (Fig. 1A, B).