The extracellular domain of FNDC5 is proposed to be cleaved into a peptide hormone named 'irisin' after the Greek messenger goddess 'Iris'. Irisin has been shown to play an important role in various physiological conditions. Irisin has been shown to be in increased levels in muscle tissue after exercise in some studies, whereas, others showed no effect of exercise on irisin levels. Several studies shown that, irisin reduce insulin resistance, adiposity and the effects of other adiposity-based pathological conditions. In this book, we presented whether the commercial antibodies generated...