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.

Input: Consider Input: Histamine enhances the depolarizing afterpotential of immunohistochemically identified vasopressin neurons in the rat supraoptic nucleus via H1-receptor activation.

Output: vasopressin


Input: Consider Input: RDH12, a retinol dehydrogenase causing Leber's congenital amaurosis, is also involved in steroid metabolism.

Output: retinol


Input: Consider Input: Use of the norepinephrine transporter as a reporter gene for non-invasive imaging of genetically modified cells.


Output: norepinephrine