Recombinase-mediated cassette exchange (RMCE) replaced the expression cassette between the JT15 and lox2272 sites of Gt(ROSA)26Sortm1Maoh with CAG promoter-rox-EGFP-poly(A)-CAT (chloramphenicol acetyltransferase)-poly(A)-rox-tdTomato-poly(A) cassette. Flp-mediated recombination removed the extra sequence flanked by FRT sites. The EGFP expressed ubiquitously from the CAG promoter switch to tdTomato expression in the cells expressing Dre recombinase. (J:173808, J:303408)