Third, saliva-specific markers,HTN3 and STATH, were detected in saliva from all donors. Crossreactivity was observed between saliva and the vaginal secretionspecific marker, MUC4, (an average of 597 RFUs) and at a low level (an average of 12 RFUs) with the menstrual blood-specific marker,MMP7 (Fig. 2C). The average peak heights of both HTN3 and STATH were significantly different from that of MUC4 (p = 7.4 1021 for HTN3 and p = 4.2 1054 for STATH). Differences in cross-reactivity between individual donors were observed. Cross-reactivity was present in some of the 1:10 and 1:50 dilutions of the MUC4 marker (Table 2).