Rabbit Anti-Human EBAG9 polyclonal antibody for IHC-P. RCAS1 (Receptor binding cancer antigen expressed on SiSo cells, Estrogen receptor-binding fragment-associated gene 9 protein, BAG9) is a type III transmembrane protein that is predominantly located in the Golgi. It induces apoptosis of natural killer (NK) /T cells and plays a role in immune invasion, possibly in relation to Epstein-Bar virus infection. RCAS1 is abundantly expressed in prostate cancer cells when compared to normal epithelial cells, and immunodetection of RCAS1 expression can be a negative prognostic indicator for patients with prostate cancer