Moreover, as perivascular astrocytes have a supportive role in the maintenance of the brain–blood barrier [55], and netrin-1 has been found to support blood–brain barrier integrity and protect the central nervous system against injury [56, 57], we speculate that netrin-1 and DCC may also play a positive role in the restoration of the brain–blood barrier after cerebral ischemia, which also needs further clarification. The gene discussed is NTN1; the disease is brain ischemia.