Early activation antigen CD69 is also known as C-type lectin domain family 2 member C (CLEC2C), Activation inducer molecule (AIM), Early T-cell activation antigen p60, Leukocyte surface antigen Leu-23. CD69 contains one C-type lectin domain. CD69 / CLEC2C is expressed on the surface of activated T-cells, B-cells, natural killer cells, neutrophils, eosinophils, epidermal Langerhans cells and platelets. CD69 is induced by antigens, mitogens or activators of PKC on the surface of T and B-lymphocytes and by interaction of IL-2 with the p75 IL-2R on the surface of NK cells. CD69 / CLEC2C involved in lymphocyte proliferation and functions as a signal transmitting receptor in lymphocytes, natural killer (NK) cells, and platelets.