Recipients of 10%/90% mixtures of LTα−/−/μMT-TNFΔARE/+ and LTβ−/−/μMT-TNFΔARE/+ BM should also be impacted by TNFΔARE/+ induced ileitis, but for these mixtures, all B cells would lack either LTa or LTb. Here, LTB is linked to Crohn ileitis.