We have found that the overexpression of PD-linked alpha-synuclein, parkin and DJ-1 proteins enhanced ER-mitochondria Ca2+ transfer by favoring ER-mitochondria juxtaposition, and provided evidence that through this action, physiological amounts of these proteins are able to tune ATP production (Calì et al., 2012b, 2013b; Ottolini et al., 2013). The gene discussed is PRKN; the disease is Parkinson disease.