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.

[Q]: However , these compounds did not have a significant effect on SDF1 alpha - induced mitogen - activated protein kinase activity .
[A]: SDF1 alpha

[Q]: A significantly higher suppression was achieved after sequential exposure of PBM cells to cortisol and equimolar levels of prostaglandin E2 ( PgE2 ) .
[A]: prostaglandin E2

[Q]: Progesterone receptor ( PR ) level was analyzed in some specimens with the use of a similar method .
[A]:
Progesterone receptor