NFKB1 and infectious otitis media: To investigate whether inflammatory signaling pathways were altered in IRF9-deficient mice after DSS administration, we measured the activation of NF-κB and p38 mitogen activated protein kinase (MAPK) and found them to be similar in the colon of WT and IRF9-deficient mice 14 days after AOM/DSS treatment (Figure 3A).