Lynch Syndrome X-Talk of Enteral Mucosa With Immune System

Inclusion Criteria (for participants with Lynch syndrome): * Age ≥18 years * All sexes eligible * Established diagnosis of Lynch syndrome performed as part of clinical practice, with a germline pathogenic/likely pathogenic variant in one of the following genes: MLH1, MSH2, MSH6, PMS2, and EpCAM * Subjects with Lynch syndrome undergoing surveillance gastrointestinal endoscopy and/or surgery according to clinical practice * Fertile patients (both males and females) are eligible * Lactating women are eligible Inclusion Criteria (for participants without Lynch syndrome): * Age ≥18 years * All sexes eligible * Patients with sporadic colorectal lesions, including colorectal cancer and colorectal adenomas * Healthy controls without colorectal cancer or adenomas undergoing lower gastrointestinal endoscopy for abdominal pain * PREMM5 \< 2.5 \[PREMM5 is an online, free-to-use, clinical prediction algorithm that estimates the cumulative probability of an individual carrying a germline mutation in the mismatch repair genes responsible for Lynch syndrome\]. Exclusion Criteria (for participants with or without Lynch syndrome): * Age \< 18 years; * Diseases that are known to predispose to colorectal cancer (personal past or recent history of inflammatory bowel disease); * Patients unable/unwilling to provide consent; * Pregnancy