What is eternal life?

1. Polio vaccine: A vaccine developed by Hela cells has saved 650,000 lives so far. 2. Dolly the sheep was cloned: the technology of isolating single cells was invented, which laid the foundation for cloning Dolly the sheep. 3. Reasons for immortality: Active telomerase makes Hela cells replicate indefinitely. So far, the total weight of HeLa cells has reached 50 million tons, which can circle the earth three times together.