UK383367 resulted in an increased amount of C-pro/α1(I) on collagen fibers by immunostaining and Western blotting (WB) from cultured CAFs (Supplementary Fig. 2E–I) and decreased total collagen I deposition by WB in a dose-dependent manner in cultured CAFs (Supplementary Fig. 2G–I) and cancer cells (Supplementary Fig. 2J), confirming that it is an inhibitor of BMP1. Here, BMP1 is linked to cancer.