When exogenous AA was added to the host cells following LTA induction, the expressions of ARPC3 and ARPC4 in the pathway of bacterial invasion of epithelial cells were observed to be significantly downregulated when compared with LTA alone, indicating that AA can protect the host cells by regulating their expression and reducing the invasion efficiency of S. aureus. The upregulation of CHMP3 expression in the endocytosis pathway is a noteworthy point, and some studies have reported that it can promote the invasion of breast cancer cells by inhibiting CHMP3 expression (35). The gene discussed is ARPC4; the disease is breast carcinoma.