However, at 12 and 18 months, compared to age-matched Nfkb1+/+ animals, Nfkb1−/− mice have a higher incidence of several observable age-related characteris-tics including rough fur coat, alopecia, rectal prolapse and paraphimosis (Fig. 1A, Table 1). The gene discussed is NFKB1; the disease is Rectal prolapse.