Final answer:
When a gene knockin is made in mice, the gene of interest is inserted into the genome. This is an example of a gene knockin.
Step-by-step explanation:
When a gene knockin is made in mice, the gene of interest is inserted into the genome. This is an example of a gene knockin. The gene of interest is inserted into another gene, often using a plasmid vector or transposons, so that it becomes part of the mouse's genome.