FAP and esophageal squamous cell carcinoma: The mean plasma FAPα values from the ESCC patients (57.55 ± 23.48 ng/ml), CRC patients (52.09 ± 24.63 ng/ml) and liver cancer patients (70.83 ± 30.56 ng/ml) were significantly lower than those from the healthy controls (87.78 ± 44.37 ng/ml) (P = 0.008; P = 0.004; P = 0.033, Figure 1A).