Disease-associated mutations have also been identified in genes that encode target proteins of ubiquitination including RIP1 and NEMO. Patients with autosomal recessive RIP1 deficiency are immunodeficient, as characterized by lymphopenia and recurrent infections, and develop inflammatory enterocolitis that resembles inflammatory bowel disease (IBD) (Cuchet-Lourenco et al., 2018; Abed et al., 2019; Uchiyama et al., 2019). This evidence concerns the gene RIPK1 and lymphopenia.