To date, there is no evidence of the expression of this molecule by macrophages and oral epithelial cells in response to periodontal pathogens such as A. actinomycetemcomitans. However, our data show that A. actinomycetemcomitans has the ability to induce TSLP expression in epithelial cells and to a much greater extent in macrophages compared to unstimulated cells, opening the possibility of studying this molecule as one of the key mediators in the response of the first cells that come into contact with the pathogen in the initial stages of periodontitis. The gene discussed is TSLP; the disease is periodontitis.