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.

Example Input: 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 .
Example Output: MHC tetramers

Example Input: It is a pterin 4alpha - carbinolamine dehydratase that is involved in the regeneration of the cofactor tetrahydrobiopterin during the phenylalanine hydroxylase - catalyzed hydroxylation of phenylalanine .
Example Output: cofactor tetrahydrobiopterin

Example Input: Glucocorticoid receptor levels and steroid induced inhibition of nucleic acid precursors have been examined in lymphocytes from 27 patients at different stages of chronic lymphatic leukaemia .
Example Output:
Glucocorticoid receptor