This book describes the central role of the human ribosome in health and disease. In health, the ribosome is responsible of life, because it synthesizes all the macromolecules that sustain life in all kingdoms of life. In an infectious disease such as COVID-19, the ribosome is responsible of the synthesis of all the viral proteins and enzymes that are needed by the SARS-CoV-2 virus for infection, for the replication of its RNA genome and for the multiplication of viral particles. Therefore, an effective anti-COVID drug must transiently block the human ribosome in order to prevent it from synthesizing the proteins and enzymes that are needed by the virus to spread. All the drugs that can achieve this task are listed in this book. Similarly, the human ribosome is directly responsible of the hyper-proliferation of cancer cells. The control of the activity of the ribosome by targeting it with anticancer drugs is therefore a very interesting approach. Finally, the mechanism of the ribosome is unknown, and this book describes the new insights into its functioning that make it easier to understand the precise role of this ribonucleoproteic particle in health and disease.