Fig. 3. FAP knockdown alters the tumor microenvironment. (A) Immunohistochemical staining for CD31 (top row) and Picric-Sirius Red staining for collagen (bottom row). Magnification, 20×. (B) Average numbers of CD31⁺ per high-power field (magnification, 40×). In each case, 6-10 fields were selected for counting. *P ＜ 0.001 compared with controls. (C) Western blotting assay. Representative Col-I and β-actin protein bands, as well as Col-I expression normalized to β-actin.