Microsatellite instability as a driving force for cancer progression

Impaired cellular DNA repair mechanisms are greatly involved in cancer initiation and progression. In the present paper we would like to draw attention to microsatellite instability (MSI) a part of genomic instability that characterizes cancer cell and to propose its role in cancer initiation and the promotion of cancer progression. We believe that malfunctioning of mismatch DNA repair (MMR) plays an important role in cancer, sometimes as the main driving force and sometimes as an influential bystander. Appearance of MSI as a consequence of MMR deficiency has many potential clinical implications. It can be used for assessment of cancer risk, precision grading, and prognosis as