IL10RA and hyperinsulinemic hypoglycemia, familial, 4: As Il10ra-/- mice were only available on the C57BL/6 background, and do not develop spontaneous colitis in our vivarium (data not shown), Il10ra-/- mice were crossed to cytokine deficiency-induced colitis susceptibility (Cdcs)1 congeneic mice (C57BL/6) (Bleich et al., 2010).