While investigating the effect of metformin on CRC stem cell apoptosis and proliferation via microRNAs (miRNAs), recent research demonstrated that metformin reduces the expression of CD133 mRNA in CD133+ SW480 and HCT116 CRC stem cells by increasing the levels of miR-342-3p in an environment with a high glucose concentration [53]. The gene discussed is PROM1; the disease is colorectal carcinoma.