<blockquote>The mouse floated in the air in the middle of its cage.
It was an ordinary lab mouse, with white fur, beady red eyes, and an adorable little pink nose. The left ear was tattooed with a constellation of dots that identified it uniquely from all its siblings and cousins. A small nick in its tail showed where I’d taken a tissue sample soon after it had been born. The fact that it was alive today, a fully grown thirty-one-gram adult, showed that it had passed that test: it carried a modification in CHRNB2, the cholinergic receptor nicotinic beta 2 subunit gene, which we hoped would positively affect its ability to socialize with and learn from its peers.
The mouse looked at me. I looked back.
It clutched a shiny blue marble in its front paws.</blockquote>
➤ the one with the experimental mice who help patch a leak on a space station
