Influenza viruses are becoming increasingly resilient to medicines. For this reason, new active ingredients are needed. Important findings in this regard have been provided: for the virus to proliferate, the polymerase of the influenza A virus has to be modified many times through enzymes in the host cells. The team of researchers was able to produce a comprehensive map of types of modification. Medicines directed against the enzymes woud be resilient to rapid mutations in the virus, thus offering great potential for the future.