In addition, Cu exposure significantly reduced glutaredoxin (GRX1) activity in neuroblastoma cells due to Cu-binding activity of the latter, whereas Grx1 overexpression significantly reduces mitochondrial Cu accumulation despite the overall higher cellular Cu content and copper transport protein 1 (Ctr1) up-regulation (De Benedetto et al., 2014). Here, GLRX is linked to neuroblastoma.