FAP modulates the expression levels of stromal α-SMA and assorted ECM molecules. Western analyses were used to determine the levels of desmoplastic marker α-SMA and assorted ECM proteins underlying the matrix differences mediated by FAP expression. The normalized fold ratios of the selected proteins by loading controls (β-actin or GAPDH) were assigned as one arbitrary unit. Compared to FAP- matrix proteins, α-SMA, fibronectin, and collagen I were significantly up-regulated in FAP+ 3D matrices (p = 0.009, p = 0.002, p = 0.001, respectively), while tenascin C was significantly down-regulated (p = 0.001). Note that although collagen I levels were rescued (p = 0.007) by inhibition of FAP activity during matrix production (FAP+inhibitor), levels of expression of fibronectin and α-SMA were only significantly increased when compared to FAP- (p = 0.04 in both cases) but not to FAP+ (p = 0.32 and p = 0.61, respectively). *denotes statistical significance.