A TI{KozakGAL4} DNA cassette has been inserted into Hs2st, replacing the coding sequence (coordinates of deleted sequence are 2L:19443300..19444687 , release 6 genome). This results in a simultaneous knock-out of Hs2st plus a knock-in of GAL4 that is expected to be expressed under the control of the endogenous regulatory sequences of Hs2st (predicted to gene trap all annotated transcripts of the gene). The deletion also removes part of RanGAP. The TI{KozakGAL4} cassette was inserted via the CRISPR/Cas-9 drop-in technique, using a dsDNA donor vector with homology arms of length 200bp. The sgRNA sequences used to target the gene were: ATTTATTTCAGCATAATCTCAGG and TTCGGCCCAAATGATTGCAGAGG.