Preface: Special memorial issue dedicated to Kendric Smith

This issue of Photochemistry and Photobiology is dedicated to the memory of Kendric C. Smith (October 13, 1926—November 1, 2024). Kendric was an authority on radiation and ultraviolet light pathobiology. His research interests included DNA repair and mutagenesis following radiation exposure. Kendric published over 200 scientific papers and authored or edited 12 books. He received his B.S. degree in Chemistry from Stanford University in 1947. He carried out his doctoral work at the University of California, Berkeley, where he received his Ph.D. in Biochemistry in 1952. Kendric then accepted a faculty position at the University of California, San Francisco Medical Center in 1953. In 1956, he joined the faculty of Stanford University Medical School and was promoted to Professor of Radiation Oncology in 1973. We are honored to celebrate Kendric's memory. He played a pivotal role in the establishment and development of the American Society for Photobiology (ASP). Many of us came to know him through his activities at the ASP. Not only did he found the ASP in 1972, but he was also appointed its first president in 1973. He was an inspirational figure and provided advice and support to those who served as ASP President, including Al Girotti in 1995, Frank Gasparro in 1996, Tayyaba Hasan in 2010, and Alexander Greer in 2020. Kendric also shared inspirational remarks at the ASP Biennial Meeting in Albuquerque during the Past Presidents' Bridges-to-the-Future (BTTF) Symposium in 2022. This BTTF event marked the 50th anniversary of the establishment of the ASP and was organized by Frank Gasparro and Albert Girotti. Kendric reflected on the origins of the ASP and described the evolution of our society and its journey toward becoming an international photobiology community. The event offered an opportunity to look back to its origins in 1972 and to seek inspiration to propel the ASP toward a rich and successful future over the next 25 and 50 years (see graphic below). This special issue features a total of 15 contributions. Topics covered span UV carcinogenesis, ALA-enhanced PDT with an iron chelator, photodynamic priming, immunomodulatory effects of PDT for skin cancer, multifunctional agents and metal-containing sensitizers for PDT, and nonmelanoma skin cancers. Additional studies examine singlet oxygen generation from thioguanine and benzo[a]pyrene excitation, pterin photooxidations, DNA damage repair, and sequencing of DNA photoproducts. Research involving photo-assisted synthesis in ring fusion, and photoswitching and photochromism is also featured. We are pleased to present this special issue of Photochemistry and Photobiology in honor of Kendric's memory. We also thank the contributing authors for helping to make it a success.