Technical Articles

Microsatellite instability (MSI) is a crucial molecular biomarker in multiple solid tumors, including colorectal cancer, gastric cancer, and endometrial cancer, and it holds several clinical significances. The occurrence of MSI is closely associated with the abnormal function of the mismatch repair system (MMR).

The MMR system plays a crucial role in maintaining genomic stability. During DNA replication or recombination, errors such as base mismatches, small-scale base deletions, or insertions are inevitable. The MMR system, like a meticulous "proofreader," can accurately identify these errors and initiate the repair process. It mainly relies on the coordinated work of proteins encoded by key genes such as MLH1, PMS2, MSH2, and MSH6.