To assess the relevance of RI in human CD4+ T-cell mediated diseases, we conducted RANKPEP restriction analysis for three diseases characterized by dominant CD4+ T-cell mediated pathogenesis and strong associations with specific MHC II haplotypes and known or suspected eliciting antigens: Lyme disease (OspA/DRB1*0401),(24) celiac disease (gliadin/DQ2.5)(25) and multiple sclerosis (myelin/DRB1*1501/02)(26) (Table 3). The gene discussed is CD4; the disease is Lyme disease.