Chronic inflammation is clearly associated with an increase in the risk of cancer. Non-steroidal anti-inflammatory drugs (NSAIDs) are well documented as agents that inhibit tumor growth and with long-term use can prevent tumor development. NSAID-activated gene (NAG-1), a unique member of the TGF-beta superfamily, is highly induced by NSAIDs and numerous drugs and chemicals with anti-tumorigenic activities.

The protein product of NAG-1 is first formed into an immature peptide dimer that must be cut at a specific site before it can be secreted as a mature protein. Currently available antibodies can only detect either the immature form of NAG-1 or the secreted mature protein, but do not recognize the peptide fragment that remains when the immature dimer is cut to form the mature protein. Now available for the first time, the present new antibody recognizes this NAG-1 pro-peptide fragment.