Body & HealthFact
The largest gene family in your genome works in your nose.
Humans have around 400 functional olfactory receptor genes plus some 600 switched-off copies. Mice have roughly 1,400 active ones. Every smell activates a pattern of several receptor types at once – like a chord. Linda Buck and Richard Axel won the 2004 Nobel Prize in Medicine for this.
Useful: With 400 building blocks and combinations, you can tell apart far more smells than you have receptor types.
Source: en.wikipedia.org