DNMT1 and colonic neoplasm: Herwijnen et al., collected sucrose gradient (1.12–1.18 g/ml) fractions from human and porcine milk showed abundant of let-7 family members and miR-148a67, a series of centrifugations and filtrations combination of ExoQuick regent for human milk exosome isolation was proofed that miRNA-148a is a highly expressed miRNA and down-regulated PTEN (phosphatase and tensin homolog) in normal fetal colon epithelial but not in colon tumor cells, and milk-derived exosomes deleted of miRNA-148a, which inhibited proliferation and DNMT1(DNA methyltransferase 1) expression in cells68.