ACTA1 and neoplasm: Importantly, the changes in the ECM produced by FAP+ fibroblasts effectively recapitulate many aspects of stromal ECMs, including increased tumorigenic behaviors [37], enhance ability to metastasize in vivo [41], promote epithelial cancer cells to move along insoluble tumor-associated ECM fibers leading them towards the intravasation sites during metastasis [48], and recapitulate pancreatic stromal characteristics, such as increased collagen I expression and up-regulation of desmoplastic marker α-SMA [49].