Definition of "knockin"

The advantage of this design is that the targeted knockin retains the intact endogenous aggrecan locus and expresses the tamoxifen-inducible CreERT2 protein from a second IRES-driven open reading frame.

2015 July 8, “Non-Invasive Quantification of Cartilage Using a Novel In Vivo Bioluminescent Reporter Mouse”, in PLOS ONE‎