Detailed Instructions: 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: A complete inhibition of DNA synthesis by dexamethasone ( Dx ) could be observed when IL 2 - depleted cultures of CTL were either incubated for 6 h with the hormone prior to the addition of IL 2 or treated simultaneously with Dx and a low concentration of IL 2 .
A:
IL 2