Variable baseline proliferation rates of TIL were observed among individual patients, but overall co-culture in the presence of hexameric GITRL doubled the numbers of CD4+ and CD8+ pMMR CRC- and CRLM-derived TIL compared with TIL stimulated in the presence of αCD3/CD28 alone (Figure 7B–D). Here, CD4 is linked to colorectal carcinoma.