“FGF is not exactly a nutrient,” said Andrew Stout, who was at the time lead researcher on the project and is now director of science at Tufts Cellular Agriculture Commercialization Lab. “It’s more like an instruction for the cells to behave in a certain way. What we did was engineer bovine muscle stem cells to produce these growth factors and turn on the signaling pathways themselves.”

Source: Cultivated Meat Production Costs Could Fall Significantly with New Cells Created at Tufts | Tufts Now