Abstract
Knockout mice obtained by homologous recombination technology may be valuable tools for in vivo investigations in toxicopathogenesis. A short review is given on the phenotype of mice with distinct deletions of cytokines and related genes. The application of these mice in pharmacological and toxicological research is discussed, with emphasis in endotoxic shock, hepatic toxicity, and myelotoxicity. The use of such knockout mice will be valuable for mechanistic studies in toxicology.