We found a severe decline in the number of Eya-positive mature cyst cells in the c587-GAL4>UAS-bel RNAi testes compared with control testes of c587-GAL4 males (3.36 ± 7.95 cells, n = 25 versus 46.3 ± 18.21 cells, n = 10, p = 4.528∙× 10−6 (Wilcoxon/Mann–Whitney test) (Figure S2C; Figure 1G). The gene discussed is LGALS4; the disease is cyst.