We have efficiently generated the first monoclonal antibody (MAb) against the human ZNRD1 protein, a transcription-associated protein, consisting of two zinc ribbon domains. Hybridomas were screened by indirect enzyme-linked immunosorbent assay (ELISA) using either purified 6 x His-ZNRD1fusion protein or purified 6 x His-OS-9 fusion protein as a control. One MAb named H6 (IgG(1)), effective in detecting the recombinant and cellular protein, was characterized by ELISA and Western immunoblotting. Thus, it binds to native ZNRD1 protein and should be useful in studies of ZNRD1 protein function and expression. By Western immunoblotting analysis of 16 patients with gastric cancer using the MAb, we found ZNRD1 protein was more overexpressed in incision margin than in carcinoma tissue. The results showed that ZNRD1 might be a novel modifier in gastric carcinogenesis.