Creatine kinase (CK) is a type of enzyme that catalyzes the conversion of creatine and ATP into phosphocreatine and ADP, facilitating energy transfer. The family includes subtypes CK-MM, CK-MB, and CK-BB, each composed of two subunits, primarily found in tissues like muscle, heart, and brain. Creatine kinase plays a crucial role in maintaining cellular energy balance, muscle contraction, and nerve conduction. The expression of creatine kinase is tissue-specific, and mutations or dysregulation of its expression are associated with various diseases, including myocardial infarction, muscular disorders, and neurological conditions. The activity of creatine kinase is regulated by various factors, affecting cellular metabolism and function.