Model Description: A IRES-CreERT2-pA expression cassette was knocked into the Prox1 gene stop codon site. Prox1 encodes a transcription factor (prospero-related homeobox 1) that is necessary for the formation and maintenance of lymphatic vessels. When Prox1-IRES-CreERT2 mice are bred with mice containing loxP-flanked sequence, tamoxifen-inducible Cre-mediated recombination will result in deletion of the floxed sequences in PROX1positive cells.