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]:  This approach uses reporter - plasmids for the detection of intracellular signals mediated by the mitogen - activated protein kinase or cyclic AMP - dependent protein kinase .
[EX A]: reporter - plasmids

[EX Q]:  MHC tetramers , which constitute a labeled MHC - peptide ligand suitable for binding to the Ag - specific receptor on T cells , provide a novel approach for the detection and characterization of such rare cells .
[EX A]: MHC tetramers

[EX Q]:  Further studies show that genes governing the expression of class II antigens fall into at least three complementation groups ; two of these were previously unidentified in mutant cell lines generated in vitro .
[EX A]:
class II antigens