This peptide is an antagonist variant of OVA (257-264). It induces positive selection on the beta 2M (-/-), and negative selection on beta 2M (+/-) background. This peptide was used to study the ability of the wild-type or mutant TCRs to transduce signals leading to positive or negative selection, and was utilized in several thymocyte development studies. E1 presentation leads to Egr-1 induction and ERK phosphorylation.