In this task, you are given a sentence. You are expected to recognize the name of any form of chemical substances. Although there might be several correct answers, you need to write one of them.
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Question: Breast cancer and steroid metabolizing enzymes: the role of progestogens.

Answer: steroid


Question: Activity-dependent cleavage of brain glutamic acid decarboxylase 65 by calpain.

Answer: glutamic acid


Question: Mercury induces the expression of cyclooxygenase-2 and inducible nitric oxide synthase.

Answer:
nitric oxide