To date, a few miRNAs (miR-520 h [36,37], -519c [16,17], -328 [18], -181a [38], & -487a [39]) have been identified by different research groups independently to regulate ABCG2 expression by interacting directly with ABCG2 3′UTR and to determine the sensitivity of cancer cells to chemotherapeutic drugs (Table 1). This evidence concerns the gene ABCG2 and cancer.