The let-7-5p microRNAs (miRNAs), commonly downregulated in HCC, have established roles in controlling post-transcriptional gene regulation of ABC transporters (eg, multidrug resistance-associated protein 5 MRP5/ABCC5) and some oncogenes (eg, RNA-binding protein LIN28B). The gene discussed is ABCC5; the disease is hepatocellular carcinoma.