NOS2 and liver dysplastic nodule: Based on the biphasic regulating effects of Huangqi on the generation of NO by macrophages in vitro, a second hypothesis is proposed: the therapeutic effects of Huangqi on different stages of DN may be due to effective intervention with some processes of the disease, such as activation or inactivation of iNOS in macrophages and increase or decrease in NO production, at different stages of DN, and at different states of the patient, thereby reversing the imbalances of the disease condition.