As soon as it was possible to purposefully modify the DNA of economically important organisms, a whole branch of modern biotechnology emerged, which tried to adjust these organisms and their use mainly (but not only) for the food and pharmaceutical industry. The very first GMO commercially available in the form of food was Flavr Savr tomato (launched in 1994), which included a gene that slowed its rotting. The product of this gene prevented the natural formation of the enzyme polygalacturonase, which degrades the cell walls on the surface of the tomato, reducing the firmness of the fruit and enabling a faster onset of rotting. For this reason, tomatoes might begin to rot even before they reach the store shelves. Growers often solve this by picking unripe fruits and later treating them with ethylene, which signals the cells to begin ripening. When using this trick, however, they do not have time to create all the necessary substances in the fruits and thus might end up "tasteless". Flavr Savr tomatoes did not suffer from this, because even though they were picked after they were already ripe, the fruits were still fresh for sale or production. Like all GMOs, these tomatoes had to go through a strict inspection by the Food and Drug Administration (USA) before being put on the American market, which excluded them from posing a risk to consumers or the environment. The first GMO animal used for human consumption was the AquAdvantage salmon (introduced in 2015), which is genetically modified in such a way that a gene regulating growth hormone activity allows this salmon to feed and grow not only in the spring and summer (like regular salmon), but through the entire year. Thanks to this modification, the salmon grows to much larger sizes and generates larger amount of meat.