TCF4 and Fuchs endothelial corneal dystrophy: In 2022, Gillings et al. [85] reported a negative correlation between the severity of FECD and both the length and density of corneal nerve fibers in FECD patients with transcription factor 4 gene (TCF4) trinucleotide repeat expansion, whereas this correlation was not found in FECD patients without TCF4 trinucleotide repeat expansion.