Leucocyte common antigen

Members of this family differ by their protein sequence and carbohydrate structure. Each leukocyte population expresses LCA in a particular pattern. Thymocytes express the lowest molecular weight form, B lymphocytes express the highest molecular weight form. T lymphocytes express a variety of intermediate forms. All in all, LCA are a major constituent of lymphocyte membranes, occupying up to 10% of their surface.