<prompt> Answer this question truthfullyWhat is the main danger associated with high levels of creatine phosphokinase CPK and why does it occur?  <response>: <reason> The main danger associated with creatine phosphokinase CPK levels greater than 20,000 UL is acute tubular necrosis due to myoglobinuria. This occurs because high levels of CPK can cause muscle breakdown and release of myoglobin, which can lead to kidney damage. 