By observing the type, density and location of immune cells within the TME, survival in CRC can be predicted more accurately than with the traditional TNM system (67), leading to the development and implementation of the immunoscore, a robust and consistent standardized scoring system based on the quantification of two lymphocyte populations (CD3 and CD8) at the tumor center and invasive margin (68). By classifying cancers according to immune infiltration, the system introduces the four proposed types of tumour based on Immunoscore: hot, altered(excluded, immunosuppressed) and cold. The gene discussed is CD8A; the disease is cancer.