IMO the most well defined and worthwhile castle to be taken will be oncology.

Beating cancer has been said multiple times but I think we will get it this time.

I believe so because we seem to have already the right sized tools for the job, like understanding the nature of carcinogenesis, the fact that nature already gave us some good weapons to fight it (the immune system) and that deep down the entropy of the problem is not so big.

Senescence/dementia/getting old is much trickier.

Cancer will end up the way infectious diseases did, IMO.

PS Im an oncologist…