MKNK1 and breast cancer: To first check if RRs had the ability to target Mnks and peIF4E proteins, we probed the effect of RRs in comparison with ATRA, 4-HPR and the Mnk inhibitors-CGP57380 and cercosporamide on the expression of Mnk1 and p-eIF4Eser209 in BC cells by western blotting.