The JNK MAPK inhibitor SP600125 was used to demonstrate that SP induced cytokine and NGF expression in keratinocytes required JNK activation. SP600125 completely blocked SP (10−8M, black bars) stimulation of TNF (A), IL-1 (B), IL-6 (C), and NGF (D) gene expression in keratinocytes at 3 h, measured by real time PCR. CGRP treatment did not induce JNK activation (Fig. 7), thus CGRP was not tested against a SP600125. Values are means ± SE. * P<0.05, ** P<0.01, and *** P<0.001 vs vehicle treated control cells. # P<0.05, ## P<0.01, and ### P<0.001 vs SP treated cells. These experiments were repeated 3-4 times.