Programmed cell death — the body’s controlled process for eliminating cells that are damaged, old, or no longer needed.Distinct from necrosis, which is uncontrolled cell death that triggers inflammation. Apoptosis is tightly regulated and essential for normal development and tissue homeostasis. Several neuroprotective peptides (humanin, NAP) work by inhibiting apoptosis in neurons under metabolic stress. In oncology, inducing apoptosis in cancer cells is a core therapeutic goal.