Small-Molecule SIK Inhibitor Induces Tanning in Human Skin Sample (image) Massachusetts General Hospital Share Print E-Mail Caption Cultured human skin treated for eight days with a small-molecule SIK inhibitor (right) shows a significant increase in pigmentation. Areas treated with a control substance (left) or an SIK inhibitor less able to penetrate human skin (center) show no darkening. Credit Nisma Mujahid and David E. Fisher, MD, PhD, Cutaneous Biology Research Center, Department of Dermatology, Massachusetts General Hospital Usage Restrictions Usage restricted to coverage of the research described in this release. 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.