TCF7L1 and psoriasis: Furthermore, psoriasis and SCC are skin diseases both characterized by keratinocyte dysregulation with overexpression of NGAL and transcription factor 7-like 1 (Tcf7l1), its regulator, as reported by Xu et al. [48] Their in vitro study on human foreskin keratinocytes (HFK) demonstrated that NGAL expression increased with the Tcf7l1 level in HFKs undergoing differentiation and decreased significantly upon Tcf7l1 depletion.