LGALS4 and cyst: Genetic ablation of CySCs is accomplished by using the cyst lineage driver C587-Gal4, Gal80ts to drive expression of the pro-apoptotic gene grim in adult testes (C587-Gal4, Gal80ts > UAS grim); after grim expression is withdrawn, hub cells in most testes re-enter the cell cycle, eventually giving rise to new CySCs (Hétié et al., 2014).