By using the non-isotopic single-strand conformation polymorphism (SSCP) technique to analyse products of the polymerase chain reaction (PCR), we detected a 561-adenine to cytosine substitution resulting in an amino acid exchange from serine to arginine at position 128 of the E-selectin gene. If this amino acid substitution has an effect on the adhesion of blood cells to the endothelium, the polymorphism could be of interest with respect to association studies in a number of pathological conditions, such as cardiovascular diseases.