Dsup is a tardigrade protein that can help shield DNA from some forms of radiation damage, acting a bit like a protective wrap around chromosomes. Early mouse and human-cell work is promising, but it also behaved badly in nerve cells, so this is not a simple universal shield.

Bowhead whales seem to use CIRBP as part of a very careful DNA-repair system that helps cells fix breaks cleanly. Human-cell and fly experiments look encouraging, but nobody has yet shown that it makes mammals live longer or resist cancer safely.

SOD2 helps mitochondria clean up reactive oxygen stress, which sounds like it should slow aging. In long-running mouse studies, extra SOD2 reduced some damage but did not extend lifespan, making it more of a survival helper than a longevity switch.

CAHS D is a tardigrade protein that helps cells cope with drying-like stress by forming reversible protective structures. It works modestly in human cells under lab stress, but true mammalian drying survival remains far beyond current evidence.

Deinococcus uses PprI and related repair systems to survive radiation levels that would destroy most life. A few mouse and human-cell studies suggest PprI can reduce radiation damage, but the result needs independent replication and safer delivery ideas.

Melanized fungi from extreme environments can absorb radiation and neutralize damaging chemistry, which may explain part of their toughness. The more exotic idea that they harvest radiation like food is still debated, and melanin can also make tumors harder to treat.

Weddell seals store huge amounts of oxygen in muscle using myoglobin that stays soluble at extreme concentrations. The diving phenotype depends on whole-body physiology, so seal myoglobin alone is not yet a proven upgrade for mammalian cells.

Antifreeze proteins from polar fish stick to tiny ice crystals and slow their growth, which is useful for preserving cells and organs. They are promising for cryobiology, but chronic use in living bodies is unproven and too much can damage tissue.