In order to study host cell signaling pathways that are altered during Yp infection, including pathways that are modulated independently of the TTSS mechanism, we compared host response of 16HBE14o- cells (human bronchial epithelial cells) infected with the fully virulent strain CO92 with the response to infection with a derivative avirulent strain, CO92 (Pgm-, Pst-). This evidence concerns the gene VCAN and infection.