Virology is the study of viruses and virus-like agents, including (but not limited to) their taxonomy, disease-producing properties, cultivation and genetics. It is often considered a part of microbiology or pathology. In the early years this discipline was dependent upon advances in the chemical and physical sciences, but viruses soon became tools for probing basic biochemical processes of cells.Viruses have traditionally been viewed in a rather negative context as agents responsible for disease that must be controlled or eliminated. However, viruses also have certain beneficial properties that can be exploited for useful purposes (for example in gene therapy or vaccinology).