Dr. John Koo is the former vice chairman of the department of dermatology at the University of California San Francisco. He is also the former director of the Psoriasis, Phototherapy, and Skin Treatment Center at UCSF, which is one of the largest phototherapy centers in the United States. Dr. Koo is an expert in the management of psoriasis with decades of experience in overseeing phototherapy for patients with psoriasis, as well as other photo-responsive skin conditions. He also oversees the Goeckerman program at UCSF. Dr. Koo has published various books on psoriasis treatments, including the series Mild to Moderate Psoriasis and Moderate to Severe Psoriasis, both of which include detailed chapters on phototherapy. Dr. Koo is known to be a key opinion leader and world expert in psoriasis. Dr. Mio Nakamura is a psoriasis and clinical research fellow currently training under Dr. Koo. Dr. Nakamura currently assists in overseeing the phototherapy and Goeckerman units at UCSF. She is involved in clinical research for psoriasis, including a trial on a novel dosimetry protocol for Excimer laser.