MYD88 and escherichia coli infection: As expected, the expression of A20 was much lower in MyD88−/− BMDM cells than in WT groups (P < 0.05); furthermore, we failed to detect the downstream protein p-P65, in MyD88−/− BMDM cells stimulated by GAS (Figure 6A), suggesting that the expression of A20 is mainly dependent on the MyD88 signaling pathway in BMDM cells following GAS or E. coli infection.