CCND1 and inflammatory bowel disease: In addition, our recent work has established MG53 as an E3 ligase of cyclin D and repressing the growth of colorectal tumors by promoting cyclin D1 degradation.20 Though our preliminary data suggest that the protective function of MG53 in IBD does not require E3 ligase activity, further investigation will determine whether the E3 ligase activity and membrane repair function contribute to the MG53-mediated protection against IBD.