This book presents a theoretical multiscale modeling framework for the integration of processes spanning from molecular signaling to individual and collective cellular behavior to complex spatiotemporal dynamics at the tissue and organ levels. It then gives a detailed discussion on how to incorporate experimental and patient data into the modeling framework. The book also illustrates multiscale modeling approaches through several applications, including breast cancer and mammary gland development, lymphoma and leukemia growth, the investigation of biobarriers to chemotherapeutic drugs, and nanoparticle-based delivering strategies.