Foetuses at 15th weeks show tight, shiny and smooth skin associated with a lack of thymus, anencephaly and spina bifida, indicating that beside its role in the thymus and skin epithelium, FOXN1 might also be involved in neurulation in humans [72];Infant mutants demonstrate complete alopecia of the scalp, eyebrow, and eyelashes and nail dystrophy associated with a primary severe T-cell immunodeficiency [23,73]. The gene discussed is FOXN1; the disease is spina bifida.