In the reporting period we have continued serological characterization of cancer patients undergoing vaccine trials. We have selected 16 previously identified serological cancer markers for further evaluation. In the pilot experiment with Dr. Schlom lab (NCI) we observed elevation of humoral immune response against several antigens in patients immunized against CEA. Similarly, in collaboration with Dr. E. Jager (Frankfurt) we observed elevation of humoral immune response not only against NY-ESO-1 (which was the target of vaccination), but also against few other antigens. We have evaluated and characterized serological response against thymidilate synthase in patients after 5-FU based therapy, and against tankyrase 2 in colon and breast cancer patients. Our data indicate that serological arrays we developed are useful cancer biomarkers for disease monitoring.