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:  Binding of progestins to the glucocorticoid receptor .

Answer: glucocorticoid receptor


Question:  To study the presence of estrogen - binding sites ( EBS ) in the synovial tissues of male and female patients with rheumatoid arthritis ( RA ) and in age - and sex - matched healthy controls .

Answer: binding sites


Question:  Among six or so PKC isoforms expressed in T cells , only PKCtheta participates in the assembly of the supramolecular activation clusters at the contact site of the TCR with Ag .

Answer:
PKC isoforms