Some of the most important include activation by des-gamma carboxy prothrombin (DCP), which is highly secreted by HCC cells [182]; interaction with other receptors, such as EGFR, integrin, beta-catenin, CD44, MUC1, and FAK [177,183,184]; hypoxia and miRNA loss [185]; and receptor-activating mutations and amplification [177]. The gene discussed is CD44; the disease is hepatocellular carcinoma.