The specificity of the Tc24 hydrolysis reaction was demonstrated by the ability of IgMs purified from non-Tc24-exposed mice to hydrolyze Tc24 but not other non-BC-SAgs, including Na-ASP-2 from N. americanus, TSST and LukS-PV from S. aureus, or dispersin from E. coli suggesting that the activity reported was Tc24 specific. This evidence concerns the gene PSAP and breast cancer.