PD153035 (125 nM), PD184352 (125 nM), SP600125 (25 μM), p38 MAP kinase inhibitor IV (1 μM) and Protein Kinase A inhibitor fragment 14:22 (10 μM) are chemical inhibitors of the EGFR, ERK1/2, JNK, p38 and PKA signaling molecules, respectively. All inhibitors used were purchased from Sigma Aldrich and resuspended in DMSO. The cells were pre-treated with the inhibitors for 1 h and then co-incubated with the inhibitors and bacteria (MOI 100) for 2 h at 37°C and 5% CO2. In the experiments with N. gonorrhoeae the cells were co-incubated for 4 h. Following incubation, adhesion assays and qPCR analysis was performed as described in the sections above.