TCF7L1 and actinic keratosis: Intriguingly, TRANSFAC-based motif analysis identified TCF7L1 as one of the 17 transcription factors whose targets are significantly altered between normal skin and premalignant tumors (papilloma/actinic keratosis) as well as between premalignant and malignant skin tumors (SCC) in both human and mice (Chitsazzadeh et al., 2016).