The mouse promoter from BAC clone 26630 was used to drive inducible icre expression in smooth muscle cells. An FRT-flanked beta-lactamase gene contained within the cre/ESR1 cassette was removed by flp mediated recombination. The transgene that originally integrated into Chr Y was found to to have translocated to Chr X in some female mice in the colony. The exact position is unknown. (J:248193)