The key findings of this analysis are (i) that ALT flares may occur in approximately 25% of patients in the first 24 weeks of PEG‐IFNa treatment, and in an additional 10%–15% of patients during follow‐up after treatment, (ii) that these ALT flares did not result in any liver failure—even in patients with cirrhosis, but (iii) that ALT flares may be considered as beneficial as more than half of the patients showed a HDV RNA decline within two visits after an ALT flare, and some patients who experienced flares also lost HBsAg. The gene discussed is GPT; the disease is Cirrhosis.