The nonapeptide P2X5a (HLA-B*07:02) TPNQRQNVC peptide is the naturally presented epitope at the cell surface by HLA-B7 molecules recognized by CTL RP1 TPNQRQNVC is a linear peptidic epitope (epitope ID179916) studied as part of P2X purinoceptor 5 from Homo sapiens (human), tested in T cell assays