Oncology is the branch of medicine that focuses on the diagnosis, treatment, and research of cancer. Oncologists specialize in various types of cancer and employ treatments such as surgery, chemotherapy, radiation therapy, immunotherapy, and targeted therapy. Oncology is also a therapeutic area in clinical research, where studies aim to develop new treatments, improve existing therapies, and understand cancer biology. Contract Research Organizations (CROs) often offer services in this therapeutic area to help clinical researchers expand therapies, treatments, and devices for people suffering from various cancers.