Msh6, a key DNA mismatch repair (MMR) gene, is crucial for maintaining genomic stability by rectifying errors that occur during DNA replication [2,6]. It functions as part of the MMR system, which is involved in pathways related to preventing mutations and maintaining the integrity of the genome, thereby playing a significant role in preventing cancer development [2,3,4,5,6,8].

Germline Msh6 mutations are more prevalent in endometrial cancer patient cohorts (3.8% truncating and 2.9% missense) compared to hereditary non-polyposis colorectal cancer (HNPCC) cohorts (2.6% truncating and 4.4% missense), and genomic rearrangements are not a major contributor to Msh6 mutations [1]. In Lynch syndrome, variants in Msh6 are difficult to classify due to low cancer penetrance, but two integrated functional-analysis-based procedures can effectively classify these variants [2]. Among microsatellite instability-high solid tumors, Msh6 mutations are the most common (25.7% among tumors with MMR gene mutations), and tumor mutational burden varies based on the underlying MMR gene alterations and tumor histology [3]. Msh6 mutations are associated with lower cancer risks compared to MLH1 or MSH2 mutations in Lynch syndrome [4]. Maternal exposure to dibutyl phthalate can regulate Msh6 crotonylation, impairing homologous recombination in fetal oocytes [7].

In conclusion, Msh6 is essential for DNA mismatch repair and genomic stability. Research on Msh6, including studies involving its mutations, has provided insights into its role in various cancer-related conditions such as endometrial cancer, HNPCC, and Lynch syndrome, as well as its impact on early meiotic events in fetal oocytes. Understanding Msh6 is crucial for uncovering the mechanisms of cancer development and reproductive disorders.