To elucidate this further, the possible mechanisms inducing human HCC are classified into four groups: growth factors and their receptors (TGF-α) [16,17]; the reactivation of developmental pathways (Wnt) [18]; oncogenes (K-ras) [19]; and tumour suppressor gene (p53) [20,21]. The gene discussed is TGFA; the disease is hepatocellular carcinoma.