This is why you only have 5 fingers

[@jalynnkarlie5542]

*promo sm*

[@liamrileyborres]

Is it actually called sonic hedgehog???

[@sammckaylin]

The guy who named it needed a name for a protein in the same family as European and Indian Hedgehog. His wife brought a magazine home and there was an advert for Sonic in it. The rest is history! en.wikipedia.org/wiki/Sonic_hedgehog_protein