Identification of the restriction element responsible for the observed T cell response. ELISPOT assay with CD8+ T cells from patient UC-098 presensitized with NY-ESO-1 peptide 80-109 and tested against partially histocompatible B-EBV targets pulsed or not with NY-ESO-1 peptide 94-102. The complete class I haplotype from UC-098 is indicated on top, matching target alleles are shown in bold and italic print.