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.

 Expression of oestrogen and progesterone receptors by mast cells alone , but not lymphocytes , macrophages or other immune cells in human upper airways .
progesterone receptors

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

 Cycloheximide , a reversible protein synthesis inhibitor , is thought to block DNA replication in normal cells by preventing synthesis of a labile protein .

labile protein