The top 20 pathways (Figure 4C) included lipid metabolism (glycerolipid, cholesterol, fat digestion and absorption and glycerophospholipid), immune regulation (Th1 and Th2 cell differentiation, hepatitis B and breast cancer), and endocrine function (parathyroid hormone synthesis, secretion and action, and endocrine resistance). The gene discussed is PTH; the disease is hepatitis B virus infection.