A bowhead whale can live beyond 200 years and carries roughly a thousand times as many cells as a human, yet it is not highly cancer-prone. A 2025 study found that its defence may not be extra tumour-suppressor barriers, as in elephants, but extraordinarily efficient and accurate DNA repair that prevents dangerous mutations from accumulating in the first place.

A bowhead whale can live beyond 200 years and carries roughly a thousand times as many cells as a human, yet it is not highly cancer-prone. A 2025 study found that its defence may not be extra tumour-suppressor barriers, as in elephants, but extraordinarily efficient and accurate DNA repair that prevents dangerous mutations from accumulating in the first place.

Bowhead fibroblasts proved easier to transform than human cells in one test, yet accumulated fewer mutations because their DNA-break repair was unusually efficient and faithful.