RSPO2 and polycystic kidney disease: Phenotypic enrichment analysis found that 9 PSGs (AKAP11, ARHGAP35, BMP7, GPC3, NEK1, PMEPA1, ROBO1, RSPO2, and SLC26A7) were closely associated with increased urine osmolality, hydroureter, polycystic kidney, and kidney development.