MYH1 and neoplasm: Class I myosins play roles in different cellular processes, such as intracellular transport, formation of cell surface projections, regulation of endocytosis, exocytosis and phagocytosis and importantly in membrane tension and cell migration and recently has been shown that they could contribute to cancer initiation and progression by different mechanisms, some of them as tumor suppressors, others increasing cancer cell motility and consequently metastasis, as we proposed for Myosin 1 g, and others favoring cell proliferation and avoiding differentiation.