The translated FOXN1, Foxn1, proteins are nonfunctional in human and mice, respectively and lead to similar defects [23,24,25];Pleiotropic mutation categorised into two independent phenotypic responses: (i) impaired skin keratinisation and aberrant HFs development [13,19,23] and (ii) thymus dysgenesis that leads to T-cell deficiency [23,67];. This evidence concerns the gene FOXN1 and congenital T-cell immunodeficiency.