HOXA1 and neoplasm: In summary, HOXA1 may mainly exert tumor regulation functions through the following four mechanisms: spatiotemporal expression disorder (high expression in cancer tissues, especially in the cell nucleus), abnormal protein-signaling pathways (neuronal protein secretion), mediation of immunosuppression (inhibition of CD8+ T cell infiltration) and aberrant epigenetic activity (high expression of HOXA1 leads to a decrease in DNA methylation level).