RAC1 and infection: The infection of skin keratinocytes by S. aureus can involve several mechanisms, including the utilization of sphingosine 1-phosphate and its receptor, integrin-linked kinase, Rac1, the Chemerin-CMKLR1 axis, fibronectin-binding protein, and multiple high-affinity fibronectin-binding repeats within fibronectin-binding protein A (Edwards et al., 2011; Bur et al., 2013; Nguyen et al., 2018; Igawa et al., 2019; Chen et al., 2024).