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.

 The action of these hormones possibly involves the synthesis of an inhibitory protein ( s ) , since the presence of cycloheximide during the incubation with Dx prevented the inhibition of DNA synthesis .
inhibitory protein

 The differential timing of CD4 and HLA - A2 downmodulation may have implications for HIV pathogenesis and immune evasion .
HLA - A2

 Corresponding enzymatic activity was detectable only for 17 - hydroxysteroid dehydrogenase and 5alpha - reductase , respectively producing testosterone and 5alpha - dihydrotestosterone .

5alpha - reductase