Fatty Acid Synthase (FASN) is a multifunctional enzyme complex critical for de novo lipogenesis, catalyzing the synthesis of long-chain fatty acids from acetyl-CoA and malonyl-CoA. It plays a central role in energy storage and membrane formation, with elevated activity linked to metabolic disorders (e.g., obesity, diabetes) and cancers. FASN overexpression in tumors is associated with aggressive phenotypes, chemoresistance, and poor prognosis, making it a potential therapeutic target. Antibodies targeting FASN are essential tools for studying its expression, localization, and function in biological systems. These antibodies are widely used in techniques like Western blotting, immunohistochemistry (IHC), immunofluorescence (IF), and flow cytometry to assess FASN levels in tissues, cell lines, or clinical samples. Researchers also utilize FASN antibodies to investigate regulatory mechanisms (e.g., post-translational modifications) and validate gene silencing/knockout models. Specificity and validation are crucial, as FASN exists in multiple isoforms and interacts with various co-factors. Commercial FASN antibodies are typically raised against epitopes in conserved regions (e.g., thioesterase domain) and are available in different host species (rabbit, mouse) with diverse conjugates. Proper controls, including knockout validation and tissue-specific expression patterns, are recommended to ensure antibody reliability in experimental settings.