Analysis of LAG3 overexpression on TILs has revealed evidence for a pathological role, which involves down-regulating the immune response for various cancer entities, such as chronic lymphatic leukaemia, colorectal cancer, ovarian cancer, melanoma and hepatocellular carcinoma, leading to a worse prognosis in LAG3 positive malignancies (Shapiro 2017; Li 2013; Hemon 2011; Huang 2015; Chen and Chen 2014). This evidence concerns the gene LAG3 and colorectal cancer.