CCND1 and hepatocellular carcinoma: Raf-1 proto-oncogene (RAF1), a MAPK pathway component that is aberrantly activated in HCC, can indirectly downregulate cyclin D1 (CCND1), matrix metallopeptidase 2 (MMP2) and cytoskeleton genes like paxillin (PXN), which are crucial for tumor cell migration, focal adhesion and consequential metastasis [65,83] (Figure 3).