We could detect FAP activity in the plasma of naive, 4T1 tumor bearing and cisplatin treated 4T1 tumorous animals with the following average AUC (± SEM) values from HPLC analysis: 518.5 ± 55.5 × 103, 1240.2 ± 77.9 × 103, 914.9 ± 71.7 × 103, respectively (Figure 3). Here, FAP is linked to neoplasm.