To further evaluate the requirement for TAK1 activation during TRAF3-regulated hepatic steatosis in vivo, the TAK1 inhibitor 5Z-7-ox was intraperitoneally (i.p.)administered to NTG and TRAF3-LTG mice, and the inhibitory efficacy of this compound was confirmed by the reduced phosphorylation of TAK1 (Fig. 7a). The gene discussed is OPA1; the disease is fatty liver disease.