Registration has opened for the 2021 Advanced Comprehensive Toxicology course. The materials for the 2021 course will be available for online viewing by registrants by the July 15, with access available until October 1, 2021! This advanced course is a complement to the Toxicology for Pharmaceutical and Regulatory Scientists course. The virtual lectures will cover detailed descriptions of the principles of toxicology, effects of xenobiotics on organ systems, discussions of specific classes of toxicants, mechanisms of toxicity, risk assessment, and other contemporary toxicological concepts. The content of this course will provide information that may be helpful to those seeking certification in toxicology or to those seeking advanced training in toxicology.