It is also worth acknowledging that, unlike RIPK1-deficient mice that die perinatally, patients with biallelic loss-of-function mutations in RIPK1 survive into early adulthood but do develop primary immunodeficiency typified by recurrent infections, as well as clinical manifestations including oral/skin lesions, arthritis, and early-onset IBD [98,99]. This evidence concerns the gene RIPK1 and inflammatory bowel disease.