Wickham et al. [14] have described a modular arrangement of OI-122 genes based upon their association with each other across HUS-associated non-O157 STEC strains: module 1 contains Z4318, pagC, and Z4322; module 2 contains Z4323, sen, nleB, and nleE; and module 3 contains the efa gene cluster. This evidence concerns the gene MORF4 and hemolytic-uremic syndrome.