Figure 10.3 Cre-lox deletion:

10.2 Humanized mouse:

A mouse carrying functional human genes or cells is called humanized. Humanized mice are made by introducing the functional copy of a human gene into a recipient mouse in the form of expression plasmid. The mice containing the functional copy of a human gene are bred with a knockout mouse. Alternatively the humanized mouse can also be made by directly injecting the human transgene into pronuclear embryos from mice that are knockout for the corresponding murine gene. In addition, the human gene can also be introduced using a routine homologous recombination in embryonic stem cells with the corresponding mouse gene.