MAPK8 and pachyonychia congenita: In another study, quercetin promoted tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis in TRAIL-resistant PC cells [124], and decreased cellular FLICE-like inhibitory protein (cFLIP) expression, while activated c-Jun N-terminal kinase (JNK), leading to the proteasomal degradation of cFLIP and eventually making PC cells more susceptible to TRAIL-induced apoptosis [124].