Hongshik Ahn’s specialty is tree-structured regression modeling for censored survival data. After earning his Ph.D., he initially worked as a biostatistician at the National Center for Toxicological Research (NCTR) on animal carcinogenicity, developmental toxicology, and drug stability analysis. He came to Stony Brook in 1996, but continued working on NCTR problems while developing new collaborations with Stony Brook biomedical researchers. His research has been funded by NIH.