MMR deficiency is associated with telomere shortening in leukocytes of cancer patients with Lynch Syndrome, in tumors with microsatellite instability and in normal primary human lung fibroblasts depleted of hMSH2 (Rampazzo et al., 2010; Mendez-Bermudez and Royle, 2011; Segui et al., 2013; Garrido-Navas et al., 2020). Here, MSH2 is linked to Lynch syndrome.