With that said, recent genetic engineering technological advances such as CRISPR/Cas9 and other CRISPR systems further hone the ability to make these changes. As far as I am aware, the lab grown meat that has been publicly shown has not been genetically modified. But I am almost certain this will not hold true over time. The first type of modification that may be implemented may be the creation of genetically modified animals where myostatin is knocked out. Myostatin is a protein encoded by the MSTN gene which essentially functions to inhibit myogenesis. In doing so, it keeps muscle growth in check. Randomly occurring mutations in the myostatin gene have led to the identification of animals with abnormally larger muscles, including humans [Figure 12, 54]. Researchers are now exploring engineering strategies to make these animals commercially, as they provide more lean muscle than standard farming strategies [55, 56]. Human athletes are also exploring this, through use of the myostatin inhibitor follistatin for performance enhancement or even anti-aging strategies [57, 58]. Thus, harvesting satellite cells from MSTN knockout animals or through the creation of in vitro MSTN knockout cell lines will likely lead to higher yields of skeletal muscle tissue.