Definition

Describes a way of grouping cells or microorganisms, such as bacteria or viruses, based on the antigens or other molecules found on their surfaces. For example, human papillomaviruses (HPVs) are a group of many related viruses, and each virus in the group has its own serotype. The serotypes can cause the viruses to behave differently when they infect people. For example, some HPV serotypes can cause benign (not cancer) tissue growth, such as warts, while others can cause certain types of cancer.