Alternatively, as here observed, the early phase of PHH may, in part, arise subsequent to IVH-induced hypersecretion of CSF [9, 14], as also observed with ischemic stroke-induced hyperactivation of NKCC1 in choroid plexus [46] and aligned with inhibition of NKCC1 ameliorating IVH-mediated ventriculomegaly in rats [14, 47]. The gene discussed is SLC12A2; the disease is ischemic stroke.