Actually, the differentiation of Th1 cells and Th2 cells depends on the cytokines they are exposed to; in the DNCB-induced ACD animal model, cytokine IL-18 and IL-10 induce Th1 differentiation while IL-4 causes Th2 differentiation and antagonizes Th1 development [31, 32]. Here, IL18 is linked to granular corneal dystrophy type II.