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 Q]:  Expression of oestrogen and progesterone receptors by mast cells alone , but not lymphocytes , macrophages or other immune cells in human upper airways .
[EX A]: progesterone receptors

[EX Q]:  Syk is not demonstrably associated with the internalized receptor .
[EX A]: internalized receptor

[EX Q]:  The Epstein - Barr virus promoter initiating B - cell transformation is activated by RFX proteins and the B - cell - specific activator protein BSAP / Pax5 .
[EX A]:
RFX proteins