Researches in CE patients and secondary hydatid mouse model indicate that, during the late stage of hydatid infection, the Th2 cell humoral immunity is dominant and the imbalance of Th1/Th2 plays an important role in promoting the immunopathogenesis change of this disease, accompanied by secretion of cytokine IFN-γ and IL-4 [3, 5–7]. Here, IFNG is linked to cholesteryl ester measurement.