To further study the functional impact of Gata6 on the MMR pathway, we used two methods that are key to diagnosing Muir–Torre syndrome (Eisen & Michael, 2009b) and Lynch syndrome (Giardiello et al, 2014): microsatellite instability (MSI) testing and immunohistochemistry for MMR proteins. The gene discussed is MRC1; the disease is Lynch syndrome.