CBLN4 and Parkinson disease: Worthy of mention is that some PSGs without known behavioral phenotypes are associated with human mental illnesses, e.g., CBLN4 (Alzheimer’s disease [33]), WBSCR17 (Parkinson’s disease [34, 35], autism [36]), and ASTN2 (autism [37–42], Alzheimer’s disease [43, 44], intellectual disability [45, 46], schizophrenia [47, 48], and attention deficit/hyperactivity disorder [40, 49–51]).