"The practice of cloning clones indefinitely appears to be a reproductive dead end, for now."

But by the 58th generation, according to Wakayama’s team, the mice did not even survive for more than a day.

Article being reported on: https://www.nature.com/articles/s41467-026-69765-7

Bracketed text my own to reduce the sensationalism of the headline. I also would argue against the summation that it is a 'reproductive dead end.' Even though indefinite cloning doesn't appear possible, it's still impressive how far it can go and apparently even late-gen clones could still theoretically reproduce sexually.