Microsatellite Instability (MSI)

Description

Microsatellite instability (MSI) is a condition where cancer cells lose their ability to repair DNA errors, leading to a higher number of mutations in specific DNA sequences called microsatellites. These changes can affect how well a tumor responds to certain treatments, especially immunotherapy. MSI is most commonly found in colorectal, gastric, and endometrial cancers, but it can occur in other cancers as well.