Detailed Instructions: Given an abstract, generate a keyword (a noun phrase) that best describes the focus or contribution of the paper. Such keywords can be directly from the given abstract or outside it.
Q: Abstract: A number of agents that mimic the ability of the thyroid hormone, T3, to decrease plasma cholesterol levels are described; one is as effective as T3 at reducing cholesterol levels and stimulating liver function, but has very little effect on cardiac function and is thus less likely to be toxic. The agent may be useful in the treatment of atherosclerosis.
A:
Animal