HTT and renal fibrosis: Knockdown of Gpr52 reduces HTT levels in a human tissue model, whereas neurodegeneration is suppressed by knockdown of DopEcR in Drosophila that express human HTT. The urotensin II receptor (UTS2R) is a conserved GPCR implicated in renal fibrosis by trans-modulating EGFR and activating MAPK protein (Tian et al., 2008; Vaudry et al., 2015).