CLEC1B, also known as CLEC2, is a C-type lectin-like receptor expressed in myeloid cells and NK cells. Natural killer (NK) cells express multiple calcium-dependent (C-type) lectin-like receptors, such as CD94 and NKG2D, that interact with major histocompatibility complex class I molecules and either inhibit or activate cytotoxicity and cytokine secretion. CLEC2 acts as a receptor for the platelet-aggregating snake venom protein rhodocytin. Rhodocytin binding leads to tyrosine phosphorylation and this promotes the binding of spleen tyrosine kinase (Syk) and initiation of downstream tyrosine phosphorylation events and activation of PLC-gamma-2. CLEC2 contains 1 C-type lectin domain and is expressed preferentially in the liver. It acts as an attachment factor for human immunodeficiency virus type 1 (HIV-1) and facilitates its capture by platelets.