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:
 Plasma renin activity in end - stage kidney disease .
answer:
Plasma renin


question:
 Indeed , after a single oral dose , the role of the mu - receptor agonist component of the antinociceptive effect of tramadol appears to be minor , with most of the analgesic effect being attributable to nonopioid properties of the parent compound .
answer:
mu - receptor


question:
 S1 nuclease protection mapping and primer extension analysis allowed us to propose that the A residue located 19 bp upstream from the translation initiation codon is the site of transcription initiation .
answer:

S1 nuclease