“The administration of …), sodium butyrate SB , 10(-3) M), N6,2'-O-dibutyryladenosine-3':…) M), amsacrine (mAMSA, 10(-7) M) or retinoic acid (RA, 10(-6) M) inhibits the growth activity of human promonocytic U-937 … (SB, RA, ara-C), at G2 (mAMSA) or at G1 and G2 (dbcAMP).”