Nanorobots attacking cancer. Conceptual computer artwork showing nanorobots (grey) attacking a metastasing tumour (red). This type of tumour is usually fatal, as it spreads quickly through the body, disrupting normal body function. This is an example of the future development of microscopic robot technology to treat diseases in new ways (nanomedicine). Nanorobots may be used to maintain and protect the human body against pathogens, such as cancer.