However, the Rac- and Cdc42-mediated pathways were activated only in GAS rats through the upregulation of Cd14, Arhgef, Apc, and Acta2 and the downregulation of inhibitory Tmsb4 and Ssh3 proteins, promoting actin polymerisation and stabilisation and subsequent cell migration. The gene discussed is ACTA2; the disease is flatulence.