NOS2 and cyst: Our findings showed that infiltrated proinflammatory iNOS+ MoMFs (M1) accounted for the majority of the massive number of recruited macrophages in the lesion environment during the early stage of cyst establishment in the MD and HD groups; these cells may play an important role in aiding the clearance or killing of PSCs by releasing proinflammatory cytokines or nitric oxide (NO) via NOS-2/iNOS [35], the marker for M1 macrophages [36–38].