Answer:
They act to regulate the expression of specific genes (androgen-responsive)
Step-by-step explanation:
Testosterone is a reproductive hormone in male humans. Testosterone as well as its closely related hormones e.g dihydrotestosterone, all belong to a class of hormones called "Androgens".
Androgens operate by entering into a cell and binds with specific androgen-receptor proteins (AR proteins). This contact activates the AR proteins, forming an androgen-receptor complex.
This complex then translocates into the nucleus of specific cells to bind to the DNA. Once it binds, it either inhibits or promotes the expression of specific genes (androgen-responsive). Hence, AR proteins are transcription factors because they play a significant role in regulating transcription of specific genes i.e. turning 'on' or 'off' of specific genes.
This process helps to direct the development of male sexual characteristics.