SMAD2 and hepatocellular carcinoma: Previous studies have suggested that OSER1-DT is downregulated in non-small cell lung cancer (NSCLC) and hepatocellular carcinoma (HCC) and acts as a tumor suppressor by regulating the expression of genes such as Smad2, Rab23, and ELAVL1 through microRNA sponging or competitive binding [43].