In the nucleus, HMGB1 binds with DNA to adjust the assembly of proteins with specific DNA targets; besides transcription regulation, HMGB1 also plays multiple roles in tumor development as an extracellular signaling protein, such as regulating proliferation and invasion, angiogenesis, autophagy, and apoptosis of tumor cells, participating in tumor immune response, and maintaining the metabolic growth of tumor cells, among others. The gene discussed is HMGB1; the disease is neoplasm.