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.

Input: Consider Input:  To further study the role of tTG in liver disease , we initiated investigations into the effect of a proinflammatory mediator , tumor necrosis factor ( TNF ) - alpha , on tTG activity in cultured liver cells .

Output: tumor necrosis factor


Input: Consider Input:  CAT assays demonstrated that overexpression of RXRalpha conferred the best RA response , consistent with our previous observation that 9 - cis - RA is more potent than all - trans - RA for inducing the expression of the AFP gene .

Output: AFP gene


Input: Consider Input:  Immunological studies also failed to demonstrate any significant change except for a significant increase of natural killer ( NK ) cell activity after IFN - gamma infusion .


Output: IFN - gamma