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.
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Question:  However , in a variation of this assay in which the protease is omitted , the mutant enzymes exhibited substantial levels of prolyl isomerase activity ( 5 - 20 % of wild - type ) , revealing that these mutations confer sensitivity to protease digestion and that the classic in vitro assay for prolyl isomerase activity may be misleading .

Answer: prolyl isomerase


Question:  A selective transcriptional induction system for mammalian cells based on Gal4 - estrogen receptor fusion proteins .

Answer: estrogen receptor


Question:  This cell line expresses productively rearranged immunoglobulin genes as well as the Oct - 2 gene at high levels which are comparable to those observed in activated murine splenic B cells .

Answer:
immunoglobulin genes