ARG1 and urogenital neoplasm: In the process of kidney injury, M1 macrophages promote inflammation and tubular cell apoptosis by secreting pathogenic factors such as IL-1β, TNF-α and IL-6; however, M2 macrophages reduce inflammation and promote renal recovery by secreting trophic factors such as IL-10, TGF-β and arginase-1 [33].