EUCOMM vector PRPGS00082_B_F08 was modified to replace the lacZ gene with an EGFP cassette in the exon 2. It also contains the frt and LoxP sites that allow Cre-mediated conditional targeting of the gene following Flp-mediated recombination to remove the reporter gene. RT-QPCR analysis confirmed the absence of mRNA expression in NK cells from homozygous mutant mice. (J:277150)