- Mutant Lrp1 knock-in mice generated by recombinase-mediated cassette exchange reveal differential importance of the NPXY motifs in the intracellular domain of LRP1 for normal fetal development. Roebroek, A.J., Reekmans, S., Lauwers, A., Feyaerts, N., Smeijers, L., Hartmann, D. Mol. Cell. Biol. (2006)