Metastasis of a cancerous cell. Coloured scanning electron micrograph (SEM) of a tumour cell, showing pseudopodia protrusions (bottom left and right), a prominent feature of actively motile cells. The role of pseudopodia in metastasis (the spread of cancer cells around the body) is poorly understood but it appears that a protein, named autocrine motility factor (AMF), causes pseudopodia to extend prior to cell translocation. Locomotion is integral to the entire process of metastasis.