instruction:
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.
question:
 To study B cell - specific changes that occur during the aging process , we investigated expression patterns of Pax - 5a and 5d in mature B cells of young and aged mice .
answer:
Pax - 5a


question:
 The mechanism of reducing NO production resulting from inhaled NO may involve , in part , the activities of reactive oxygen species and / or nuclear factor - kappaB .
answer:
nuclear factor


question:
 The resistance to cytolethal effects can not be ascribed to a failure of cells to take up and bind steroid or to significant differences in the molecular species of cytoplasmic receptors present .
answer:

cytoplasmic receptors