Genomics of FOXP3 Transcription Factor in T-Cell Oncogenesis Running Title: FOXP3 Transcription Factor in T-Cell Oncogenesis

Background The X chromosome encoded FOXP3 (AIID) gene is a unique regulator of T-lymphocyte differentiation and immunosuppressive function. The nuclear FOXP3 (XPID) transcription factor gene regulates lineage-specific differentiation in Treg cells and maintains immune homeostasis. The regulatory T-cell (Treg or CD4 + cells) revel a key role in the immune response to self-antigens, allergens, and tumours. However, the functional mechanisms of the FOXP3 gene are conflicted in tumorigenesis, and exhibit both tumour-suppressive and tumour-promoting effects. Empirical data suggested that the PIDX (FOXP3) gene represses tumorigenesis by affecting proliferation and apoptosis. Objective The study objective was to examine the FOXP3 gene, a member of the FOX family, in the genomes of two organisms. However, the study of the scurfin (FOXP3) gene is currently mandatory to explore the molecular phenomenon of Treg differentiation and immunosuppressive function in a particular organism. Methods The study proposed bioinformatics and computational tools and techniques to the current knowledge of the FOX family in the mammalian genome. This method may be valuable for future functional analysis of the species-specific genes and their family in particular organisms. Results A comprehensive genome-wide survey of the FOX family suggested that the FOX domain mediated genes in mammalian genomes. Further, a cross-species study suggested that the FOXP3 gene is conserved in evolution. The specific structure, domain, motifs, phylogeny, gene expression, chromosome location, and gene network study suggested that the FOXP3 gene is a T-cell-dependent gene. Also, documented data illustrated that the FOX family plays a fundamental role during growth. In contrast, the functional regulation of the FOXP3 gene exhibits tumour suppressor activity. Conclusion The study outcome concluded that the FOX family play a crucial role during development. In a ray, the restricted expression of the FOXP3 gene in the cell is an immune-privileged. Hence, the fundamental function of the FOXP3 gene in tumour cells may represent a unique mechanism in the immune homeostasis.