knock-in mouse
n.— «A “knock-out” mouse has a gene missing, a “knock-in” mouse has had one changed or substituted.» —“Genetic science alters war on animal rights” by Kirsty Milne Scotsman (Edinburgh, Scotland) Aug. 28, 2005. (source: Double-Tongued Dictionary)
Further reading
What if, instead of being an inanimate object, a dictionary were alive? That’s the idea behind a lavishly illustrated new children’s book called The Dictionary Story (Bookshop|Amazon) by Oliver Jeffers and Sam Winston. This is part of a...
Cat hair may be something you brush off, but cat hair is also a slang term that means “money.” In the same way, cat beer isn’t alcoholic — some people use cat beer as a joking term for “milk.” And imagine walking on a...