Cre-mediated excision of the parental Pip4k2ctm1a(KOMP)Wtsi allele resulted in the removal of the promoter-driven neomycin selection cassette and critical exons (exons 3 and 4), leaving behind the inserted lacZ reporter sequence. Western blot analysis of kidney tissue confirmed the absence of protein expression in homozygous mutant mice. Further information on targeting strategies used for this and other IKMC alleles can be found at http://www.informatics.jax.org/mgihome/nomen/IKMC_schematics.shtml. (J:204739, J:234283)