Provided is a T cell receptor (TCR) having a property of binding to a SLLMWITQC-HLA A2 complex; and the binding affinity of the TCR to the SLLMWITQC-HLA A2 complex is at least twice that of a wild-type TCR to the SLLMWITQC-HLA A2 complex. Also provided is a fusion molecule of such a TCR with a therapeutic agent. Such a TCR can be used alone or in combination with a therapeutic agent so as to target tumour cells presenting the SLLMWITQC-HLA A2 complex.