ACOX1 and cyst: However, using immunofluorescent confocal microscopy (Fig. 3 and Additional file 1: Fig. S10), AOX expression from the α-tubulin promoter, whether directly (Additional file 1: Fig. S10) or driven by tubGS plus mifepristone (Fig. 3), was below the level of detection in germline cells, and seen only at very low levels in some somatic cyst cells.