Apoptosis, which refers to the process of programmed cell death, plays a significant role in all stages of life, from early development to adult life. It is crucial for cell development and is integral to several critical processes including but not limited to: 

• Maintaining homeostasis in multicellular organisms
• Eliminating unwanted cells during early development, such as eliminating unnecessary cells between the fingers of a developing hand in a fetus 
• Maintaining a constant number of cells in an organism
• Maintaining the proper size of the body
• Eliminating cells that are damaged beyond repair such as cells damaged by radiation or toxins
• Eliminating dangerous T-lymphocytes
• Closure of the neural type in the dorsal part
• Removal of excess cells, such as white blood cells after an infection is completely cleared
• Removal of vestigial remnants, such as pronephros