The 13-year-old Siberian tiger Igor reacts to anaesthetics before the treatment of its hip joint with a stem-cell procedure in Szeged, southern Hungary, on April 18, 2018. Igor was treated with a new lipogems process that has already been successfully used to treat human joints in Hungary. The process cures the injured joints with a tissue taken from the patient's own fatty tissue, which contains regenerative stem cells. Igor is the world's first Siberian tiger which is treated with the lipogems self-cell procedure. (Xinhua/Attila Volgyi)?