2017). FEN increases the activity of the lipoprotein lipase enzyme, thus enhancing lipolysis, reducing the level of TG-rich lipoproteins, and elevating the level of high-density lipoproteins (HDL) concentrations, implementing additional protective effects on the cardiovascular system (Emami et al. 2020). Despite all these beneficial effects, FEN may cause myopathy and rhabdomyolysis in rats and humans (Okada et al. 2009; Wang and Wang 2018). The gene discussed is LPL; the disease is rhabdomyolysis.