In this task, you are given a sentence. You are expected to recognize the name of gene or protein. Although there might be several correct answers, you need to write one of them.

Ex Input:
A review of the structural and functional features of olmesartan medoxomil, an angiotensin receptor blocker.

Ex Output:
angiotensin receptor

Ex Input:
Expression and 1,4-dihydropyridine-binding properties of brain L-type calcium channel isoforms.

Ex Output:
L-type calcium channel

Ex Input:
Cannabinoid CB1 receptors in the paraventricular nucleus and central control of penile erection: immunocytochemistry, autoradiography and behavioral studies.

Ex Output:
CB1 receptors