TCF4 and Fuchs endothelial corneal dystrophy: Another immortalized FECD cell line, F35T, derived from a 62-year-old female FECD patient expressing TCF4 transcript with approximately 4500 CTG repeats in the intron region [91,130], has been used in multiple studies, such as trinucleotide repeat-targeting CRISPR-dead Cas9 (dCas9) as a potential treatment for FECD [81], antisense oligonucleotides to target TCF4 expansion by targeting mutant-repetitive RNA [82], and tissue-specific TCF4 triplet repeat instability using optical genome mapping [130].