Having demonstrated that the monoclonal antibody is specific for OLFM4 and recognizes OLFM4 both in normal epithelial crypt cells and in colon cancer cells, we made a sandwich ELISA for OLFM4 based on the monoclonal antibody from clone #49 as catching antibody and the monoclonal antibody from clone #40 as detecting antibody. The gene discussed is OLFM4; the disease is colonic neoplasm.