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.

Q:  Bone resorption is regulated by the immune system , where T - cell expression of RANKL ( receptor activator of nuclear factor ( NF ) - kappaB ligand ) , a member of the tumour - necrosis factor family that is essential for osteoclastogenesis , may contribute to pathological conditions , such as autoimmune arthritis .

A: nuclear factor
****
Q:  The Tip protein of Herpesvirus saimiri strain 484C binds to and activates the Lck tyrosine protein kinase .

A: Tip protein
****
Q:  Direct and indirect signaling mechanisms , including NF - kappaB activation and cytokine synthesis , were analyzed .

A:
NF - kappaB
****