Because IL-1, TNF-α, and TGF-β are increased during peripheral nerve injury in rats [21,22], it is thought that the higher NOX2 levels in the facial nerve in the injured (left) side compared with the uninjured (right) side might reflect induction of NOX2 expression by these inflammatory cytokines [9,23,24]. Here, TGFB1 is linked to peripheral nerve injury.