GBF1 (Golgi Brefeldin A Resistance Factor 1) is a member of the large ARF GEFs (ADP-ribosylation factor guanine nucleotide exchange factors) family, responsible for regulating the activity of ARF proteins, thus involved in processes like endocytosis and exocytosis. GBF1 is primarily located in the Golgi apparatus and ER-Golgi intermediate region, playing a crucial role in protein trafficking and processing. Its expression is tissue-specific, particularly high in cells with active secretion. Dysfunction or mutations of GBF1 are linked to the development of various diseases, including impacts on cell secretion functions and susceptibility to viral infections.