The uptake of bilirubin into brain at the blood–brain barrier (BBB) may occur via one of organic anion transporters OATP1, and the efflux of bilirubin from the brain may be mediated by ATP‐binding cassette subfamily B member 1 (ABCB1; also referred to as MDR1 P‐glycoprotein),35 and the expression of OATP1 and MDR1 at the BBB was reported to be upregulated after brain ischemia (Figure S4).35, 36, 37. This evidence concerns the gene ABCB1 and brain ischemia.