In mouse 3T3 fibroblasts a switch to amoeboid movement was observed upon p53 inactivation [14], while up-regulation of the Rho/ROCK signalling was found in highly metastatic rat sarcoma cells, together with the loss of MMP2 activity and an increased generation of protrusive forces, typical of the amoeboid movement [21]. The gene discussed is MMP2; the disease is sarcoma.