While this is one of the first studies to attribute a function to the presence of miR-517a/b and miR-517c in the placenta and studies in other tissues/cell types are very limited, a recent study found that over expression of miR-517a and miR-517c inhibited cell proliferation of hepatocellular carcinoma cells due to G2/M cell cycle arrest through PYK2 (PTK2B), a predicted target of miR-517a/c [53]. The gene discussed is PTK2B; the disease is hepatocellular carcinoma.