MAPK14 and pulpitis: In addition, the p38 MAP kinase signaling pathway has been reported to act as an upstream or downstream signaling pathway of NF-κB to play an essential role in the introduction of inflammatory cytokines in pulpitis.46 Therefore, the NF-κB and p38 MAPK kinase signaling pathways were both examined in vitro and in vivo, and they indicated lower levels of NF-κB and p38 MAP kinase signaling pathway activation by DPC@NPs.