ABCB1 and fetal growth restriction: Our study also shown that P300 expression, and ABCB1 (or abcb1a/b) promoter H3K9ac and H3K14ac levels were significantly reduced in the placenta in PCE-induced IUGR rats, as well as in BeWo cells treated with caffeine, and further overexpression of YB-1 can increase the ABCB1 promoter H3K9ac and H3K14ac levels.