HCD caused significant increase in the mRNA expression of transforming growth factor beta (TGF-β), Mothers Against Decapentaplegic Homolog 2 (Smad-2), Mothers Against Decapentaplegic Homolog 4 (Smad-4), Bcl-2-binding component 3 (Bbc3), caspase-3, P53 and Interleukin-6 (IL-6) and decrease in the expression levels of Cyclin depended kinase inhibitor (P21) and Interleukin-3 (IL-3) in hepatic cells. Conclusion. The gene discussed is SMAD2; the disease is heavy chain disease.