APOBEC1 (Apolipoprotein B mRNA Editing Enzyme, Catalytic Polypeptide 1) is an RNA-editing enzyme that modifies apolipoprotein B (apoB) mRNA, producing a shorter form of the protein in the intestine. This editing process is essential for lipid metabolism and the formation of lipoproteins. Dysregulation of APOBEC1 may affect cholesterol balance and is associated with studies on cardiovascular and lipid-related disorders.