Human brain gene found jumping inside poxvirus

Researchers discovered BC200, a human brain gene that can jump between genomes, embedded in molluscum contagiosum virus. The gene likely jumped into the poxvirus roughly 100,000 years ago. BC200 is essential for neuron function but retains mobility from its transposon origin, raising questions about viral transmission and disease.

BC200 was itself created from a mobile element but has retained its mobility, and yet it is also clearly serving a cellular function. Somehow evolution hasn't been able to untangle these two things.