Insertion of "T2A-Gal4-STOP-3P3-RFP", containing the GAL4 coding sequence and a 3P3-RFP marker flanked by loxP sites, into CG12338 in-frame. (Region 2R:10729128..10729641 (FB2018_02) has been replaced.) This results in GAL4 being expressed under the control of CG12338 regulatory sequences, with the CG12338 coding region intact.