(countable, uncountable, immunology) A glycoprotein found on the surface of helper T cells and several other types of immune cells. / (countable, immunology) A CD4+ helper T cell.

plural of CD4

a costimulatory protein found on antigen presenting cells and required for their activation by CD154 of T_H cells, with deficiency of CD40 possibly leading to hyper-IgM syndrome type 3.

a factor on platelets that helps bind von Willebrand factor, hence facilitating platelet adhesion and plug formation at sites of vascular injury.

a membrane protein acting as an inhibitory complement receptor, being port-of-access for measles, human herpesvirus-6 and Neisseria.

a transmembrane cell-surface sialoglycoprotein on certain immune cells, defective in Wiskott-Aldrich syndrome

enzyme involved in the regulation of signal transduction in hematopoiesis; used histologically to differentiate between lymphomas and carcinomas