T cell deficiency of Ring1a and Ring1b leads to overexpression of PAX5, which hampers their maturation and promotes their conversion to B cells.21 Moreover, Ring1a has been shown to bind to the Il4 and Ifng loci in differentiated T helper cells.22 However, the involvement of Ring1a in chronic immune-mediated IBD remains uninvestigated. Here, RING1 is linked to congenital T-cell immunodeficiency.