The RMCE cassette in the Mi{MIC}5-HT2BMI05208 insertion has been replaced with a 'Double Header' (DH) trapping cassette (contains two independent trapping modules oriented in opposite directions). The cassette is in 'gene-trap' orientation relative to 5-HT2B, which is predicted to result in truncation of the 5-HT2B coding sequence and expression of the GAL4 driver under the control of endogenous 5-HT2B regulatory sequences.