PDK4 and hepatocellular carcinoma: MiR-122 could promote sorafenib sensitivity of HCC cells through targeting and suppressing insulin-like growth factor 1 receptor (IGF-1R), serum response factor (SRF), depolymerization and metalloproteinase domain-containing protein 10 (ADAM10), pyruvate dehydrogenase kinase 4 (PDK4), solute carrier family 7 member 1 (SLC7A1) and peptide N-acetyl N-acetylgalactosaminyl transferase 10 (GALNT10) [54–58].