The TM9SF1 (Transmembrane 9 Superfamily Member 1) antibody is a tool used to detect and study the TM9SF1 protein, a member of the conserved TM9SF family implicated in intracellular trafficking and membrane dynamics. TM9SF1 is a multi-pass transmembrane protein localized primarily in the Golgi apparatus and endosomes, where it regulates vesicular transport, lysosomal function, and autophagy. It interacts with components of the endosomal sorting complex and plays roles in maintaining organelle integrity, protein sorting, and cellular homeostasis. Dysregulation of TM9SF1 has been linked to pathologies, including cancer metastasis and neurodegenerative disorders. The TM9SF1 antibody, often developed in rabbit or mouse hosts using peptide immunogens, enables the detection of TM9SF1 expression via techniques like Western blotting, immunofluorescence, and immunohistochemistry. Its applications span elucidating TM9SF1's involvement in membrane trafficking pathways, autophagy-lysosomal dysfunction, and disease mechanisms. Validation includes testing for specificity through knockdown/knockout controls. Research using this antibody contributes to understanding cellular trafficking networks and potential therapeutic targets in diseases associated with TM9SF1 aberrations.