PNLIP and periodontitis: In addition, the ERK inhibitor but not JNK or p38 MAPK inhibitor has been shown to attenuate force-mediated stimulation of NF-κB-DNA binding in hPDLCs [15], indicating the importance of ERK signalling in periodontitis and its correlation with NF-κB. Furthermore, a previous study has reported that PTL reduced IL-8 production by inhibiting both ERK and NF-κB pathways [17].