SMAD3 and brain injury: We previously showed that melatonin could ameliorate hyperglycemia-induced renal inflammation by inhibiting the activation of TLR4 and the TGF-β1/Smad3 signaling pathway and, more recently [16], melatonin was reported to have a protective effect against hemin-induced platelet ferroptosis and traumatic brain injury-induced ferroptosis [17, 18].