One report demonstrated that tumor necrosis factor-like weak inducer of apoptosis (TWEAK)-induced PKCδ enhances STAT3 activation, along with production of proinflammatory mediators in astrocytes, indicating that PKCδ is an upstream regulator of STAT3; further, these findings can be recapitulated in the MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) mouse model of PD [53]. Here, TNF is linked to Parkinson disease.