AKT1 and infection: Western blot data showed that protein levels of p-ERK were significantly upregulated at 5 and 15 minutes infection, reached peak at 45 min, and significantly decreased at 120 min when p-Akt and p-IκB were significantly upregulated (Figure 3), suggesting the involvement of ERK, Akt and IκB in the downstream signaling of P. aeruginosa infection.