The fight against Covid-19 put messenger RNA technology on centre stage. This innovation is a cause for both concern and hope. New RNA vaccines could target other viruses (Zika, Chikungunya, Ebola), heart disease, and certain cancers such as breast, skin, pancreas, larynx, and mouth. Scientists even hope to find solutions for cystic fibrosis and muscular dystrophy by combining RNA with gene therapy. Should we be enthusiastic or are these new treatments risky?