Fig. 1: Programmed cell death pathways include apoptosis, pyroptosis, and necrosis that occur when cells are subjected to various physiological or pathological stressors.

Apoptotic bodies are generally engulfed by macrophages. However, necrosis and pyroptosis compromise cell membrane integrity, causing cytolysis and release of cellular contents. These pro-inflammatory molecules may act as autoantigens; consequent inflammation will injure adjacent normal cells.