Methionine restriction upregulates miR-320d and represses its target c-Myc, thereby lowering expression of efflux mediators such as ABCG2 and increasing the sensitivity of colorectal cancer stem cells to 5-fluorouracil; this sensitization is blunted when miR-320d is inhibited or c-Myc is restored [121]. Here, MYC is linked to colorectal cancer.