CD8A and colorectal cancer: Although approaches to evaluating TILs by IHC have varied among cancer types and reports, Immunoscore has been established in the field of colorectal cancer based on reports that TILs within tumors and in the IM, including stromal regions, significantly affect prognosis.43 Immunoscore also is useful in several other solid tumors.15 Studies using Immunoscore have shown that the CD3/CD8-positive T-cell density ratio of CT to IM varies by cancer type (Supplementary Fig. 1).44–46 Few reports have compared CD45RO+ cell density between CT and IM, however.