Scientists are exploring ways to return cells to a younger state, building on a Nobel Prize–winning discovery that certain genetic factors can transform adult cells into stem cells capable of becoming virtually any cell type.[1034670] Billions of dollars from billionaires like Yuri Milner and Sam Altman are backing companies like Altos Labs and Retro Biosciences, signaling serious investor confidence in reprogramming's potential to extend healthy human lifespans.[1034670] However, past anti-aging trends have stumbled, including earlier excitement around telomere lengthening and "zombie cell" removal, which faded after disappointing human trials.[1034670][982658]