While the clinical characteristics of FECD patients with COL8A2 mutations or TNR expansions of TCF4 have been described (Igo et al., 2012), the biomechanical properties and proteome of DM in FECD patients with genotype-confirmed TNR expansions of TCF4 have not been characterized thus representing an important gap in our knowledge of this disease. Here, TCF4 is linked to diabetes mellitus.