An immunogen includes an isolated peptide of 800 amino acid residues or fewer having the amino sequence ILSAFSVYV (SEQ ID NO: 1) with four or fewer amino acid substitutions, a superagonist variant of SEQ ID NO: 1, or an amino acid sequence having the formula: (I/K/T/V/M)-L-(S/L)-(A/E/N/D/Q)-(F/V)-(S/M/V/I)-(V/D/R/G/H)-Y-(V/I/L) (SEQ ID NO: 13). The immunogens can be used in compositions and in the treatment of disorders.
