On December 31, 2020, the board of directors of Krystal Biotech, Inc. appointed Drs. Jing Marantz and Christopher Mason to serve as directors of the Company, effective as of January 4, 2021. Dr. Marantz will serve as a Class II director whose term will expire at the 2022 annual meeting of stockholders, and Dr. Mason will serve as a Class III director whose term will expire at the 2023 annual meeting of stockholders. Jing L. Marantz, M.D., PhD, MBA, age 56, has served as Senior Vice President, Medical Affairs of Acceleron Pharma since October 2020. From June 2018 to September 2020, Dr. Marantz served as Senior Vice President, Medical Affairs of Alnylam Pharmaceuticals. She served as Vice President, Global Medical Affairs for Alexion Pharmaceuticals from August 2016 to June 2018 and as Global Medical Lead for TECFIDERA at Biogen from April 2014 to June 2016. Christopher Mason, MD, PhD, FRCS, FRSB, FMedSci, age 62, has served as Founder and Chief Scientific Officer of AVROBIO, Inc. since July 2015. Dr. Mason has been on the faculty of the Advanced Centre for Biochemical Engineering, University College London since 1999, including Full Professor of Regenerative Medicine Bioprocessing (2008-2017), and Full Professor of Cell and Gene Therapy since 2017. Dr. Mason also has served as founder and director of London Regenerative Medicine Network Ltd. and OriBiotech Ltd. since February 2008 and February 2015, respectively. He previously served as founder and a director of Stem Cell Translation Ltd. from October 2006 to March 2018 and served as a trustee of the British Neurological Research Trust from May 2012 to May 2016 and the UK Stem Cell Foundation from September 2010 to May 2016.