Reverse Engineering the BH4 Pathway (IMAGE) Boston Children's Hospital Caption 'Reverse engineering' the BH4 pathway reveals sepiapterin reductase as a new target for analgesic treatments. This take on Michelangelo's famous Sistine Chapel image symbolizes the link between human pain patients and the mouse model: The lab-designed SPR inhibitor (in green), shown within the active pocket of SPR itself (in gray with its atomic structure in colored lines), is the 'bridge' between the two species. Credit Image: Alban Latremoliere Usage Restrictions None License Licensed content 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.