MAPK3 and infection: On the contrary, strains P12AB and P12CagAKO induced similar significantly higher ERK1/2 activation levels much later, after the initial 90 min post-infection (mean difference at 2 hours of 1.80 and 95%CI of 0.83 to 2.77 [P = 0.005], mean difference at 4 hours of 1.03 and 95%CI -0.13 to 2.18 [P = 0.004]), suggesting that early ERK1/2 activation may depend upon the presence of sequences surrounding the EPIYA-C motifs.