Surprisingly, we found that four crucial microRNAs (miR-34a-5p, miR-195-5p, miR-30c-5p, and miR-130b-3p) regulated the expression of many mRNAs (Cdk4, Cdk6, VEGF, IKKα, MEK1, E2F3, Rac1, E2F1, ERK1, and CDC42) and their proteins, and thus were crucial to the anti-pancreatic cancer effects of DHA. The gene discussed is MAPK3; the disease is pancreatic neoplasm.