In particular, recent data demonstrated that Porphyromonas gingivalis, one of the major pathogens involved in periodontal disease, induced platelets aggregation and the expression of several cell adhesion molecules, such as the intercellular adhesion molecule 1 (ICAM-1), the vascular cell adhesion molecule 1 (VCAM-1) and p-selectin. This evidence concerns the gene ICAM1 and periodontal disorder.