How do caspases execute apoptosis?

Caspases are a large family of cysteine proteases that play key roles in initiating and executing apoptosis. Normally, caspases exist in cells as inactive precursors or procaspases. At the onset of apoptosis, they undergo a cascade of catalytic activation and execute apoptosis by selectively targeting and cleaving specific proteins and molecules such as protein kinases, cytoskeleton proteins, caspase activated DNases, and lamins, which are present in the nucleus and cytoplasm of cells.