IFNG and infection: At the early stage of kidney injury, resident macrophages, which have an intrinsic ability for self-maintenance through proliferation [11], are activated by pathogen-associated molecular patterns (PAMPs), danger-associated molecular patterns (DAMPs) [16], interferon-gamma (IFN-γ), and pro-inflammatory cytokines [14] to differentiate into proinflammatory M1 macrophages, which are formed in response to infection or cellular damage.