No cases of liver enzyme elevation in HBsAg−/HBcAb+ anti-TNF users without antiviral therapy led to severe hepatitis or acute liver failure, and serum ALT levels in most such patients returned to normal either spontaneously, or after moderating the DMARD regimen and/or withdrawing anti-TNF agents; therefore, anti-TNF use by HBsAg−/HBcAb+ patients is probably safe. This evidence concerns the gene TNF and acute liver failure.