TMPRSS9 and Parkinson disease: A recent GWAS meta-analysis revealed the association of 12 loci, including SNCA, LRRK2, GCH1, transmembrane protein 175 (TMEM175), serine/threonine kinase 39 (STK39), transmembrane protein 229B (TMEM229B), branched-chain keto acid dehydrogenase kinase (BCKDK), microRNA 4697 (MIR4697), inositol polyphosphate-5-phosphatase F (INPP5F), Ras-like without CAAX 2 (RIT2), signal-induced proliferation associated 1 like 2 (SIPA1L2), and transmembrane serine protease 9 gene (TMPRSS9) with risk modification for developing PD [49].