Trypanosomes are parasites that cause sleeping sickness, Chagas disease, and various animal diseases. Diagnosis and treatment remain complex and no effective vaccine has been developed. A better understanding of the molecular processes in the parasite is fundamental to the development of novel effective drugs. Scientists have now characterized an important protein complex — the nuclear cap-binding complex — that is vital for trypanosomes, since it binds to the end of each of the parasites’ mRNAs.