A T cell receptor molecule (TCR) containing an alpha chain portion and a beta chain portion wherein the alpha chain portion contains three complementarity determining regions (CDRs): CDR1α: SSYSPS CDR2α: YTSAATL CDR3α: VVSPFSGGGADGLT or comprising or consisting of SPPSGGGADGLT and the beta chain portion contains three complementarity determining regions (CDRs): CDR1β: DFQATT CDR2β: SNEGSKA CDR3β: comprising SARDGGEG or comprising or consisting of RDGGEGSETQY, or wherein up to three amino acid residues in one or more CDRs are replaced by another amino acid residue. The invention also includes polynucleotides encoding the TCR molecules, and host cells containing the said polynucleotides. Patient derived T cells may have the polynucleotides encoding the TCR molecules introduced therein, and the engineered T cells may be introduced into the patient in order to combat a WT1-expressing malignancy.
