We define a TAF by four characteristics that are outlined in Figure 1B, these include fibroblast surface proteins (FAP and FSP), proteins indicative of invasion and remodeling (TSP1, Tn-C, SL-1), proteins associated with neovascularization (α-SMA, desmin and VEGF), and tumor promoting growth factors (HGF, EGF and IL6). Here, FAP is linked to neoplasm.