**2. Brief review of in vivo studies**

## **2.1 Animal studies**

Animal studies showed the involvement of sex steroid hormones in the regulation of melanoma growth, and there were also differences in the regulation of growth between male and female mice:


In the following two studies, it was shown that male mice were more prone to cancer than female mice:

d.When induced with carcinogen [18].

e.When exposed to UV-B [19].
