Transgenic animals are animals in which a foreign gene is expressed. Such animals can be used to study fundamental biological processes and phenomena, as well as for producing products useful for mankind. Give one example for each type.

(N/A) $1$. To study fundamental biological processes: Transgenic models are used to study the regulation of genes and their effect on normal physiology and development, such as the study of complex growth factors like $IGF-I$ (Insulin-like Growth Factor-$I$) and $IGF-II$ to understand how they contribute to body growth.
$2$. To produce useful products: Transgenic animals are used to produce biological products. For example, the transgenic cow 'Rosie', produced in $1997$, produced human protein-enriched milk $(2.4 \text{ g/L})$. The milk contained the human alpha-lactalbumin, which is more nutritionally balanced for human babies than natural cow milk.