Further, immunostaining of primary tumors was utilized to analyze the fiber alignment and organization of the tumor stroma in the presence of WT or Cav1 KO pMEFs, as alignment of collagen fibers in the tumor microenvironment has been shown to enhance tumor cell migration and invasion (Amatangelo et al., 2005; Provenzano et al., 2006). This evidence concerns the gene CAV1 and neoplasm.