FAP and neoplasm: It is known that FAP is a vital marker of CAFs and contributes to tumor proliferation and metastasis, which may be due to its regulation of the structure and the extracellular matrix component (Santos, Jung, Aziz, Kissil, and Puré, 2009; Lee et al., 2011; Mazur, Holthoff, Vadali, Kelly, and Post, 2016), involving in EMT and angiogenesis (Huang, Wang, and Kelly, 2004; Koczorowska et al., 2016; Wu et al., 2020), which might account for a larger proportion of advanced-stage patients in FAP-high group.