BMI1 and cancer: It has been shown that Bmi-1 is regulated by miRNAs; for instance, miR-15a is able to bind to 3′-UTR of Bmi-1 mRNA to inhibit translation [10], miR-128 can inhibit Bmi-1 expression in drug-resistant cancer cells [31], and miR-194 blocks cancer cell EMT through inhibition of Bmi-1 expression [12].