The attP cassette in the Mi{MIC}Gycβ100BMI01568 insertion has been replaced with a Trojan GAL4 cassette that contains a splice acceptor site followed by the T2A peptide, the Scer\GAL4 coding sequence and an Hsp70 transcription termination signal. The insertion is in the correct orientation to gene trap stops. The splice acceptor ensures that the T2A-Scer\GAL4 open reading frame is incorporated into the stops mRNA, while the T2A sequence is expected to truncate the native stops gene product and promotes the separate translation of the Scer\GAL4 open reading frame. Thus Scer\GAL4 expression is driven by the native stops regulatory sequences. The Mi{Trojan-GAL4.1}stopsMI01568-TG4.1 insertion is also within a coding intron of the nested Gycβ100B gene, but the inserted Mi{Trojan-GAL4.1} element is in the wrong orientation to gene trap the Gycβ100B locus.