Are you looking for an idea to start a multimillion-pound business? Proteins that stimulate cell growth currently cost several million pounds per gram, which makes them more expensive than diamonds. You need particularly lots of them if you want to grow enough cells to assemble a steak. This so-called ‘cultivated’ or ‘lab-grown’ meat was initially proposed as food for astronauts but has since turned from a science fiction fantasy to a source of hope for a more sustainable and animal welfare-conscious food for the world.