Insulin contains pig DNA.

“Until the 1980s, animal insulin was the only treatment for insulin dependent diabetes.

These days the use of animal insulin has largely been replaced by human insulin and human analogue insulin”

The quote from that site appears to speaking hypothetically,

"Genetic modification involves isolating a gene from one species, say, a frog and injecting it into the DNA of another species, such as a tomato. There are many steps in between, no doubt, but that is the essential function of genetic modification. A certain species of frog produces a chemical that, as it turns out, is anathema to pests that eat tomatoes. So the frog gene responsible for producing that chemical is inserted in the tomato DNA with the expectation that the tomato will produce said chemical and thus be immune to pests.:"

http://erewhonmarket.com/the-not-so-hidden-dangers-of-genetically-modified-food/

"GM technology reduced chemical pesticide use by 37%"

Vaccines: good
Genetically modified food: good