Anti-guanine nucleotide exchange factor antibodies are used in antigen-specific immunodetection in biological samples. The target guanine nucleotide exchange factor is a known alias name of the protein SOS Ras/Rac guanine nucleotide exchange factor 1, encoded by the SOS1 gene in humans. This 1333-amino acid residue protein is reported to promote the exchange of Ras-bound GDP by GTP. In terms of tissue expression, it is reported to be expressed in gingival tissues. Other synonyms for guanine nucleotide exchange factor include GF1, GGF1, and GINGF.