GFI1 may be a transcription factor involved in regulating the expression of genes active in the S phase during cell cycle progression in T-cells. GFI1 may be involved in tumor progression. Defects in GFI1 are a cause of autosomal dominant severe congenital neutropenia (SCN) and dominant nonimmune chronic idiopathic neutropenia of adults (NI-CINA) This gene encodes a nuclear zinc finger protein that functions as a transcriptional repressor. This protein plays a role in diverse developmental contexts, including hematopoiesis and oncogenesis. It functions as part of a complex along with other cofactors to control histone modifications that lead to silencing of the target gene promoters. Mutations in this gene cause autosomal dominant severe congenital neutropenia, and also dominant nonimmune chronic idiopathic neutropenia of adults, which are heterogeneous hematopoietic disorders that cause predispositions to leukemias and infections. Multiple alternatively spliced variants, encoding the same protein, have been identified for this gene.