Constitutive knock in
Introduce a mutation, Cre-recombinase or a reporter (e.g. beta-galactosidase, luciferase, fluorescent protein) gene into a locus of interest
Conditional knock in
The models provide you the ability to switch from the expression of endogenous gene to a mutant gene, e.g. by Cre-mediated activation of the mutation.
Humanization with knock in
Introduce a human gene to be expressed ion contrast of the mouse gene, or replace part of the mouse gene by human counterparts or repalce the 5′- or 3′-regions to the mouse gene to those of the human gene.