The amoebic Gal/GalNac lectin was characterized as the first amoebic receptor that binds to the glycoproteins galactose (Gal) and N-acetylgalactosamine (GalNAc) that are found in the mucin layer of the host and on the surface of colonic epithelial cells (Petri et al., 2002) as well as being involved in cytotoxicity processes, avoiding the action of the complement system, participating in the encystation process and producing the cyst wall (Frederick and Petri, 2005). This evidence concerns the gene GAL and cyst.