This special issue is dedicated to the fascinating intersection of Cancer Biology and Radiation Biology, aiming to understand the vital role of radiation in the field of oncology. We acknowledge that true validation often arises from a multifaceted approach and as such, we welcome contributions that incorporate various angles of research angles including radiation therapy. Radiation therapy stands as one of the most critical and important strategies for controlling or eradicating malignant cells in cancer treatment, typically administered through a linear X-ray irradiator. In this special issue we hope to publish related to mitigation of normal tissue toxicity while advancing our comprehension of cancer biology in the context of radiation therapy. We also want to have a closer look at prospective and promising combinations based on radiotherapy and drugs that target cancer-related pathways exploring their potential to impact each other.