Fibroblasts are mesenchymal cells which perform many vital functions during development and in adulthood. They are responsible for much of the synthesis of extracellular matrix in connective tissue and also play major roles in wound healing. Many diseases comprise fibroblasts; either because fibroblasts are related in their etiology or because of the fibrosis that accompanies damage to other cell types. Fibroblasts are one of the most accessible mammalian cell types and one of the easiest types of cells to grow in culture. Gingival fibroblasts are the major constituents of gingival tissue and play a key role in their maintenance. Human gingival fibroblasts (HGnF) express a wide variety of surface molecules including; CD9, CD26, CD55, CD59, CD63, CD71, CD86 CD95, CD99 and CD117. Human Gingival Fibroblasts also express mRNAs for protease-activated receptor-1 (PAR-1) and PAR-3.