CD8A and malignant colon neoplasm: However, TILs are white blood cells originated from the blood stream, they are composed of various of inflammatory cells, including lymphocytes, macrophages, natural killer cells (NK) etc. Therefore, in order to identify the phenotypic features of cells expressing IL-22 in colon cancer, IL-22 was co-stained with other cellular surface markers such as CD3, CD4, CD8, CD68, and CD3 + CD16 + CD56 in 32 cases of TILs isolated from human colon cancer tissues.