It is a process, where large areas of cells at a tissue surface or within an organ are affected by carcinogenic alterations that per se are insufficient to cause cancer but together lead to so called pre-malignant field defect, which predisposes to malignancy. By using research methods such as a high throughput RNA sequencing, we examine transcriptome changes occurring in macroscopically healthy-looking colon mucosa in Lynch syndrome mutation carriers, whom have a high risk of developing cancer. A large sample collection from colon tumors, and adjacent mucosa from LS patients and healthy individuals permit an identification of cancer preceding biomarkers and affected signaling pathways. The project is based on our previous study on the Lynch syndrome mouse model (Mlh1+/-)1,2.