Multi-cellular organisms eliminate individual cells through a self-destruct process known as apoptosis. Apoptosis is critical for proper development and maintenance of tissue homeostasis. The importance of this process is highlighted by the fact that too much or too little apoptosis is the underlying cause of pathologies such as cancer, autoimmune diseases (e.g., lupus, arthritis), and neurodegenerative disorders (e.g., Parkinson's, Alzheimer's). In the early days, apoptotic cells were identified strictly by cell morphology. Now we know that biochemical signatures define a number of death...

Phagocytosis is an evolutionarily conserved mechanism that serves as the first line of host defense in multicellular organisms. The traditional definition of phagocytosis involves the engulfment and degradation of large solid particles (>0.5 ?m), initiated by receptor activation on phagocytes. It forms an essential aspect of innate immunity through the uptake and destruction of infectious pathogens, while also participating in the removal of apoptotic cells during tissue remodeling and development. Professional phagocytes, such as macrophages, neutrophils, and dendritic cells, are well...