Four Enzymes Required for PCB Synthesis from Heme (image) National Institutes of Natural Sciences Share Print E-Mail Caption Four enzymes required for PCB synthesis from heme (HO1, PcyA, Fd, Fnr). The research group succeeded in synthesizing PCBs in animal cells by introducing these four enzyme genes. Credit NIBB Usage Restrictions None 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.