What are the functions of monoclonal antibodies?

Monoclonal antibodies serve as substitute antibodies which can enhance, restore, alter, or mimic the immune system’s attack on cells which are harmful. 

• The primary function of mAbs is to recognize and bind to specific target molecules with high precision. This binding can occur on the surface of cells, pathogens, or other molecules. mAbs can also neutralize activity of pathogens by binding to their functional sites. This prevents the pathogen from interacting with host cells and causing infection. 
• Some mAbs block the signals for cancer cells to divide, or block the receptor itself. For example, angiogenic drugs block VEGF from attaching to the receptors on endothelial cells. 
• In immune system modulation, some mAbs are designed to target checkpoint proteins, as cancer cells sometimes find a way to use checkpoints and avoid being attacked by the immune system. These drugs are known as checkpoint inhibitors. Checkpoint inhibitors don’t kill cells directly, rather, they work by helping the immune system to better find and attack the cancer cells. 
• These antibodies also have a role in drug delivery, as some mAbs have drugs or radioactive agents attached to them. The mAB then finds the cancer cells and delivers the drug or radioactive agent directly to them; these are known as conjugated mAbs.