Most clinical trials associate the myotoxic effect of statins with a circulating level of creatine phosphokinase (CPK) greater than five to ten times the normal value, but this biomarker does not invariably correlate with clinical symptoms of myopathy because an elevated CPK value can be associated with several diseases; the clinical symptom of myopathy has been difficult to evaluate and can be subjective from patient to patient [10], [11]. This evidence concerns the gene PIK3C2A and myopathy.