This is a post about penis enhancers, although not the kind that are advertised on the internet. Let me explain.

Penises and limbs are clearly very different (exaggerated references to third legs aside), but they develop in similar ways. They both involve long bits of tissue that grow out from a small embryonic bud, under the direction of very similar proteins, and molecules. For example, in 1997, Takashi Kondo from the University of Geneva showed that two genes that direct the development of legs in mice are also important for building genitals.

Now, Carlos Infante and Douglas Menke from the University of Georgia has shown that similar enhancers—sequences that switch genes on or off—are also at work