This course provides an in-depth exploration of the critical role that in vitro (cell-based) and in vivo (animal-based) disease models play in the drug development process. As the pharmaceutical industry strives to discover and develop effective therapies, the use of disease models is essential for understanding the biological mechanisms of diseases, identifying potential drug targets, and evaluating the safety and efficacy of new drug candidates. The course will cover the principles, methodologies, applications, and limitations of both in vitro and in vivo models, with an emphasis on their integration into preclinical drug discovery and development on diabetes mellitus, cancer and fibrosis.