Hao et al. (39) recently proposed that thrombin might induce hydrocephalus by downregulating endothelial cadherin in the choroid plexus, with PAR1/p-Src/p-PAK1 pathway inhibition potentially mitigating thrombin-induced hydrocephalus by upregulating endothelial cadherin expression. The gene discussed is PAK1; the disease is Hydrocephalus.