Microbiologist Dr Ron Cutler considers how a newly discovered mechanism of immune response might have implications for future treatments of the common cold. Scientists at the University of Cambridge have located an intracellular protein called 'TRIM21', which in collaboration with antibodies, is capable of killing viruses inside human cells before they have time to reproduce, spread and destroy our tissues. Writing in the Telegraph (‘Could this lead to a cure for the common cold?’, Friday 5th November, 2010), Dr Cutler states 'Although it is still early days …it is possible that future investigations into this previously unknown capability of our immune system will lead to more effective treatments against a wide variety of viral infections'.