Assertion: rat's lifespan | /r/HasProperty | around 30 years
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text: They've already discovered that mole rats have a peculiarly heavy form of the substance hyaluronon between tissues that seems to impede the creation of tumors, and that mole rats seem to build proteins spectacularly well -- both factors that could play into why their lifespan is around 30 years, nine times longer than mice [source: Poppick].