RSPO4 and multiple system atrophy: Shadrin et al. recently employed a genome-wide genetic pleiotropy-informed approach to investigate the link between MSA and seven autoimmune diseases [179], and found substantial polygenic overlap between inflammatory bowel disease and MSA with three shared genetic loci (rs4957144 in the first intron of C7, rs12740041 and rs116843836 upstream of DENND1B and RSPO4 respectively).