Scientists have said relics of ancient viruses that have spent millions of years hiding within human DNA help the body battle cancer, according to a BBC report. When cancerous cells escalate out of control, dormant remnants of these old viruses are reawakened, according to a study by the Francis Crick Institute. This resurgence of these old viruses “unintentionally” helps the body’s immune system by targeting and attacking the tumour. The study – published in the journal Nature – suggested a correlation between increased lung cancer survival and the presence of B-cells aggregating around tumours, according to the researchers. Read More: Shakib launches cancer foundation to support underprivileged patients B-cells usually manufacture antibodies in our body and are better known for their vital role in battling infections, such as Covid-19, BBC reports. Although the exact functionality of these cells are yet to be identified, it was evidenced --  based on a series of intricate experiments using samples from patients and animals – that they are attempting to fight viruses. "It turned out that the antibodies are recognising remnants of what's termed endogenous retroviruses," Prof Julian Downward, an associate research director at the Francis Crick Institute, told BBC. Retroviruses have the clever ability to insert their genetic instructions into our own. Read more: Cancer specialists for amendment of tobacco control law, increase in tobacco tax Some of these foreign instructions have been adopted over time and serve beneficial purposes within our cells, while others are tightly regulated to prevent their spread, according to the researchers. These ancient genetic instructions are no longer able to resurrect whole viruses but they can create fragments of viruses that are enough for the immune system to spot a viral threat. "The immune system is tricked into believing that the tumour cells are infected and it tries to eliminate the virus, so it's sort of an alarm system," Prof George Kassiotis, head of retroviral immunology at the biomedical research centre, told BBC. The antibodies stimulate other parts of the immune system that eliminate the "infected" cells -- the immune system is attempting to stop a virus, but in this case is eliminating cancerous cells, according to Professor Kassiotis. Read More: LabAid Cancer Hospital launches new online video commercial  Meanwhile, Dr Claire Bromley, from Cancer Research UK said that the study adds to the growing body of research that could one day see this innovative approach to cancer treatment become a reality.