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]:  T cell stage - specific PcG expression profiles suggest that PcG genes contribute to regulation of T cell differentiation .
[EX A]: PcG genes

[EX Q]:  Inhaled NO also blocked the activities of reactive oxygen species and nuclear factor - kappaB binding to DNA in lavage cells and in alveolar macrophages .
[EX A]: nuclear factor

[EX Q]:  TCF - 1 deficiency resulted in the altered usage of additional Ly - 49 receptors .
[EX A]:
TCF - 1