FOS and infection: Previous studies have demonstrated that, during infection of immortalized epithelial cells, GAS activates the AP-1, NF-κB, and MAPK pathways, leading to increased expression and secretion of key cytokines and chemokines, particularly IL-8 and IL-6 (Medina et al., 2002; Tsai et al., 2006; Klenk et al., 2007; Persson et al., 2015; Chandrasekaran and Caparon, 2016).