Anti-SPG antibodies are used in antigen-specific immunodetection in biological samples. The target SPG is a known alias name of the protein surfactant associated 2, encoded by the SFTA2 gene in humans. This 78-amino acid residue protein is believed to be a type of surfactant protein. It is localized to the Golgi, cytoplasmic vesicles, and is secreted of the cell and features N-glycosylated post-translational modifications. In terms of tissue expression, it is reported to be highly expressed in the lung, where it is detected in type II pneumocytes in the alveolus, and in nonciliated epithelium in bronchioli.