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.

Example Input: The effect of a peripheral block on inflammation-induced prostaglandin E2 and cyclooxygenase expression in rats.
Example Output: cyclooxygenase

Example Input: Effect of amrinone on tumor necrosis factor production in endotoxic shock.
Example Output: tumor necrosis factor

Example Input: Combination chemotherapy with a substance P receptor antagonist (aprepitant) and melarsoprol in a mouse model of human African trypanosomiasis.
Example Output:
substance P receptor