Wait – I know a lot of immortalized cell lines are derived from tumors.  Does this mean I’m eating cancer?  Well, not exactly.  Cancer cells have many mechanisms to avoid normal cellular checkpoints, only some of which would be similar to the methods in creating an immortalized cell line.  Additionally, the cells will likely contain additionally engineered methods to “turn off” the factors involved in immortalization to allow a smooth transition into a post-mitotic, mature skeletal myotube (or other cell type) [one example here, 53].  For this, many options are available (drug inducible, CRISPR-mediated, Cre recombinase, etc) although I am unsure exactly how the system would be set-up.  Regardless, the FDA and clean meat companies are going to have their work cut out for them in convincing the public that engineered or immortalized cells would be safe to eat.