ACS (Acetyl-CoA synthetase) is a group of enzymes responsible for converting fatty acids and coenzyme A (CoA) into acetyl-CoA. Major family members include ACS1, ACS2, and ACS3, among others, which consist of multiple functional domains and are primarily located in the cytoplasm, mitochondria, and peroxisomes. ACS plays a crucial role in regulating lipid metabolism, energy production, and biosynthetic processes. The expression of ACS family members is tissue-specific, and mutations or dysregulation in their genes are associated with various diseases, including obesity, diabetes, and cardiovascular diseases. The activity of ACS is regulated by nutritional status, hormone levels, and signaling pathways, affecting cellular metabolic balance and adaptability.