rincewitch:

beesmygod:

ppl forgot about the best/worst part of the sonic hedgehog pathway

Sonic Hedgehog also has an important role in the formation of the eyes. During early development, the cells that develop into the eyes form a single structure called the eye field. This structure is located in the center of the developing face. Sonic hedgehog signaling causes the eye field to separate into two distinct eyes.

holy shit

(via maxknightley)