Judging by sparse centenarian studies, transthyretin amyloidosis seems to be a factor limiting human lifespan to ~120 years: https://www.fightaging.org/archives/2019/07/the-question-of-...

Current understanding of amyloid diseases is improving due to race to find a treatment for Alzheimer's, so it's not inconceivable that a focused effort could find a therapy ameliorating this condition.