Mitochondrial abundant heat soluble (MAHS) proteins are localized in mitochondria and are responsible for protecting mitochondria during desiccation. Because of its role in metabolizing reactive oxygen species, the mitochondrion is an important organelle to protect in extreme environments. During dehydration, the mitochondria of tardigrades grow much smaller and lose their cristae. MAHS proteins may act to replace water in the membrane of the mitochondria, preventing uneven rehydration and membrane rupture.