Cancer brings up the fear of a growing mass spreading through the whole body causing slow unpleasant death. Indeed, it is becoming one of the biggest killer this century. Molecular science brings a whole new light to this dreaded disease. The changes in the genes are passed down through generations, and new ones are created long before we are aware of the growing tumor. In fact these same molecular changes lead to aging and many of our common chronic diseases. More importantly during the current pandemic, your immunity to covid infection is shaped by your molecular health. Prevention of cancer or other diseases is an old practice and much improved by molecular medicine. The benefits are clear for the individual and for society. Interestingly, molecular medicine not only reinforces the old concepts of good nutrition and physical activity, but also provides new tools to monitor our own molecular ecology. The unified concept of health and disease through molecular biology also extends to our apparent outside environment. What happens to our global environment impacts our very survival as a species and little did, we know that in ourselves we carry a little of the outside world, namely the microbiome we have in our gut, around our skin, and in our respiratory tract. Our health is our most asset. What we can do to maintain our best health and prevent illnesses such as chronic diseases such as diabetes and cardiovascular disease, and as in cancer, and indeed aging, surprisingly is the same program as outlined in this book.