VCAN and leiomyoma: ATRA is known to act through different pathways including MAP kinase pathway39,41,42 and protein kinase C pathway.39,43 In this study, we demonstrated an antifibrotic potential of ATRA on overall production of collagens secreted into the ECM as well as the mRNA of collagen types 1, 3 and 4, fibronectin and versican in leiomyoma cells.