SNCA and Parkinson disease: In the functional network, we highlighted several PAGs that interacted with known PD-causing genes, such as CHCHD2, RAB39B, and RIC3. CHCHD2 (Funayama et al., 2015) has been widely reported to be associated with PD, presented functional interaction with many PD-causing genes, such as SNCA, PINK1, LRRK2, PARK7, VPS35 in the network.