This transgene expresses Cre recombinase under the control of a vav promoter. This promoter was shown to be active in lymph nodes, thymus, spleen, Peyer's patches, intestinal cryptopatches, ovaries and testes. Line A2 inserted into the gene at 47022629-47022630 (Build GRCm38/mm10). The insetion results in a functional knock-out in homozygous mice.