The RMCE cassette of the TI{CRIMIC.TG4.1}CG1688CR01570-TG4.1 insertion has been replaced with a FlpTag conditional tagging cassette that is inserted in the opposite orientation to the direction of CG1688 transcription. In the absence of FLP, the CG1688 gene is not tagged, but in the presence of FLP recombinase, the FlpTag cassette is stably inverted, resulting in conditional tagging of the CG1688 gene.