Patent No. 594480 Disclosed is an agent which binds to a peptide comprising the amino acid sequence of a tumor antigen selected from the group consisting of PMWKVTAFIGNSIVVAQVVWEGLWMSCVVQSTGQMQCKVYDSLLALPQDLQAA, EGLWMSCVVQSTGQMQCKVYDSLLALPQDLQAA and RDFYNPLVAEAQK.