C3a Protein (image) Princeton University, Engineering School Share Print E-Mail Caption An international team created drug candidates based on the naturally occurring C3a peptide, the chain of molecules shown here. The C3a peptide is a key player in regulating immune responses and drugs that enhance or block its effects could be useful in treating many inflammatory diseases. Credit Journal of Medicinal Chemistry Usage Restrictions For news and other non-commercial uses. Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.