ly a clonal population of CTL) administered to the patient are substantially free of other cell types. [0020] The molecule may be any molecule at least part of which can be presented on the surface of a cell by an HLA class I (or equivalent) molecule. [0021] Preferably, the molecule is a polypeptide including a carbohydrate-containing polypeptide such as a glycoprotein or is a carbohydrate includi