Wiktionary
co-stimulation
alt. (context biology English) The requirement of T cells for two signals in order to become fully activated n. (context biology English) The requirement of T cells for two signals in order to become fully activated
Wikipedia
Co-stimulation
During the activation of lymphocytes, co-stimulation is often crucial to the development of an effective immune response. Co-stimulation is required in addition to the antigen-specific signal from their antigen receptors.