Kaźmierski et al. observed higher serum levels of OCLN, S100B, and the CLN5/zo-1 ratio in ischemic stroke patients with a clinical deterioration caused by hemorrhagic transformation [35], which indicates the similarities among the processes involved in the blood–brain barrier breakdown in adults with adverse neurological events, and the changes of the blood–brain barrier permeability in pregnancies complicated by FGR. The gene discussed is S100B; the disease is ischemic stroke.