The nuclear receptor subfamily 4 group A member 2 (NR4A2) acted as a transcription factor to regulate the expression of squalene monooxygenase (SQLE), a key enzyme in cholesterol anabolism, and the aberrant expression of SQLE led to abnormal lipid metabolism in microglia, thus promoting immunosuppression and tumor growth. The gene discussed is SQLE; the disease is neoplasm.