The Ple26-lacZ transgene (pEMS1497) was designed with the 3252 bp Ple26 minipromoter (CCL27-A; derived from one upstream and two downstream putative regulatory subregions along with a section of the promoter from the human chemokine (C-C motif) ligand 27 [CCL27] gene) upstream of a frt-flanked beta-galactosidase (lacZ) gene, an SV40 early polyA signal, and a human HPRT complementary sequence (containing exon1, intron1, exon2, and part of intron2). This construct was targeted as a single copy knockin to the Hprtb-m3 mutant locus on the X chromosome.