In HCC cells, miR-124 reduces the activity of cancer susceptibility candidate 3 (CASC3) and deactivates key molecules involved in cell proliferation, such as extracellular signal-regulated kinase (ERK), MAPK, p38, phosphoinositide 3-kinase catalytic subunit alpha (PIK3CA), and CD151. The gene discussed is CASC3; the disease is hepatocellular carcinoma.