An experimental study of genetic risk for hydrocephalus revealed that loss of the Ptpn20 gene in H-TX rats resulted in the development of communicating hydrocephalus, and the same result was observed in Ptpn20−/− mice, in which NKCC1 phosphorylation is maintained in choroid plexus epithelial cells (Xu et al., 2022). Here, PTPN20 is linked to communicating hydrocephalus.