
Previous medical mistakes in the last century were due to a lack of drug research. Given these negative impacts, long and in-depth research has become an integral component of drug testing. Without preclinical research, the emergence of new and effective drugs to help cure patients and extend their life expectancy is impossible. Preclinical studies on drugs, active substances, or pharmaceuticals are conducted on experimental animal models in vivo. In vivo models are a key component of drug discovery. They have been utilized in previous studies to explore the underlying mechanisms of many diseases and to investigate the efficacy of potential drugs before starting clinical studies in humans. The goal of this Methods Collection is (1) to provide detailed state-of-the-art protocols and procedures that are used to evaluate therapeutic or toxic effects of various compounds and (2) to introduce novel approaches that have the potential to translate into field applications. Ultimately, we believe that such in-depth sharing of knowledge will improve the efficacy of research outcomes and support a more efficient process.