Of the 800 GPCRs encoded by the human genome, roughly half are tied to smell. Smell receptors are notoriously tricky to produce in sufficient quantities for structure studies.

After centuries of mapping the human body in ever-finer detail, scientists are still making discoveries. Here we are, in 2025 ...

Researchers in the 1920s estimated that the human nose could discern around 10,000 smells 3, but a 2014 study suggests that we can distinguish more than one trillion scents 4.