Over expression of P‐gp is one of the major causes of drug resistance for various cancer cells including OS.38 Inhibition the expression of ABCB1 (P‐gp) can overcome the drug resistance of OS cells.39 We found that ERRα can bind with SP3 to regulate the transcription of ABCB1 in OS resistant cells. The gene discussed is ABCB1; the disease is cancer.