For example, in a gene therapy trial of an AAV8 vector in 10 patients with hemophilia B, participants received transgene doses ranging from 2.0 × 1011 to 2.0 × 1012 vector genomes (VG) per kg of body weight; four of six participants in the high dose group had increased ALT levels and received a tapering dose of prednisolone, and elevated ALTs resolved over a range of 2–35 days (median 5 days) [27, 28]. The gene discussed is GPT; the disease is hemophilia B.