Complement-dependent cytotoxicity

Complement-dependent cytotoxicity (CDC) is a function of the complement system. It is the processes in the immune system that kill pathogens by damaging their membranes without the involvement of antibodies or cells of the immune system.

There are three main processes. All three insert one or more membrane attack complexes (MAC) into the pathogen which cause lethal colloid-osmotic swelling ie CDC.

It is one of the mechanisms by which antibodies or antibody fragments have an antitumor effect.

CDC is measured with various assays to evaluate the effect of drug therapies.

...
Wikipedia