Wagenaar et al. conducted an in vivo study using a broad panel of HCC cell lines and evaluated the effect of specific single-strand oligonucleotide inhibitors of miR-21 on Dimethylarginine Dimethylaminohydrolase 1 (DDAH1), Ankyrin Repeat Domain 46 (ANKRD46), and RECK gene expression, and found that inhibition of miR-21 hinders the growth and proliferation of HCC cells. Here, DDAH1 is linked to hepatocellular carcinoma.