Cre-Lox is a site-specific recombinase that can be used to make deletions, insertions, inversions, and translocations at specific sites in the DNA. This is an extremely powerful genetic toolbox and has a wide range of applications. This is popularly used to create tissue-specific, inducible knockout and knockin mouse models. For generating efficient tissue-specific or inducible knock-out mice, the homozygous loxP-flanked mice should mate with a specific Cre transgenic mouse strain. Therefore effective tissue-specific Cre expression dictates the Cre-Lox recombinase activity and thus resulting transgenic mice. At TME, we use highly specific tissue-specific promoters under the regulation of tet repressor that provides highly controllable tissue-specific Cre-expressing mice to be used for all downstream applications.