[…] humans can sometimes regrow fingertips if the nailbed remains intact after injury, allowing skin, flesh, and bone to regenerate.

The process is established and described e.g. here: www.nature.com/articles/s41536-025-00441-y

The original study is over 50 years old and was focussed on children: docdroid.net/…/1972-child-fingertip-regeneration-…