B7 molecules

The major T-cell co-stimulatory molecules are the B7 molecules , B7.1 (CD80) and B7.2 (CD86). They are closely related members of the immunoglobulin gene superfamily and both bind to the CD28 molecule on T cells. They are expressed differentially on various antigen-presenting cell types. We use the term B7 molecules to refer to both B7.1 and B7.2.