Dire wolf de-extinction: Colossal Biosciences says it has resurrected an extinct animal for the first time | CNN
This reminds me of the first cloned sheep, Dolly. She died due to multiple tumors in her lungs, an expected eventuality for cloned animals.
In January 2000, a cloned sheep called Cedric died. The post mortem revealed that Cedric had died of sheep pulmonary adenomatosis (SPA). This disease is caused by a virus that induces tumours to grow in the lungs of affected animals and is incurable.
Dolly remained healthy until Monday 10 February 2003, when an animal care worker reported that he had noted her coughing. Full veterinary examinations and blood tests were conducted but failed to establish a diagnosis. A CT scan was carried out on 14 February 2003. The scan confirmed the team's worst fears: tumours were growing in Dolly's chest.
Since a general anaesthetic had been necessary to perform the CT scan, it was decided that it would be best if Dolly did not regain consciousness and she was put to sleep at the age of six.