A protein that is a translation product of the human CD69 gene or a 1:1 ortholog thereof. A type II transmembrane protein with a C-type lectin binding domain in the extracellular portion of the molecule. Involved in lymphocyte proliferation and functions as a signal transmitting receptor in lymphocytes, natural killer (NK) cells, and platelets. [ http://www.ncbi.nlm.nih.gov/pubmed/10466080 https://www.uniprot.org/uniprot/Q07108 ]