ABO blood group system
Lectin extracted from seeds of this species binds to, is remarkably specific for, and is the standard method for identification of H-substance (absent in the hh antigen system) on human red blood cells. The vast majority of humans express H-substance, which is the basis for the ABO blood group system, but a few rare individuals ("Bombay phenotype") do not—and a chemical isolated from "Ulex europaeus" is used to identify these individuals. This lectin is also used as a marker for human vascular endothelial cells, and as a tool for their isolation for in-vitro culture.