Further downregulations occurred for the PARK7-homologous peptidase PDDC1 (Glutamine amidotransferase-like class 1 domain containing 1; which interacts with the ferroptosis-induced CREB-associated PRKN-regulator TRIB3 (Tribbles pseudokinase 3)), and for the calcium-excitation factor HOMER1 (Homer scaffold protein 1) that was implicated in PD. The gene discussed is CREB1; the disease is Parkinson disease.