ARF6 and renal carcinoma: This mechanism is consistent with previously reported in vivo results: CAV1 expression in breast cancer stroma increases tumor migration and invasion [146] and CAV1 is required for invadopodia formation specifically by breast cancer cells, where CAV1 knockdown cannot be rescued by cholesterol.[147] Growing MDA-MB-231 breast cancer cells in lipoprotein depleted medium resulted in an 85% decrease in cell migration.[148] LPA activates the Arf6-based mesenchymal pathway for migration and invasion of renal cancer cells, which also originate from cells located within epithelial ductal structures.