The basis of TACA mediate tumor rejection is akin to the observation that anti-Gal IgM and IgG mediate rejection of xenograft expressing α-gal glycoconjugates with terminal Galalpha1-3Galbeta1-4GlcNAc sequences (alpha-galactosyl epitopes, natural xenoreactive antigens) that are present on various tissues in pigs and are recognized by human anti-alpha-galactosyl (alpha-Gal) antibodies (92). The gene discussed is GAL; the disease is neoplasm.