Interestingly, the Eya signal was not detected (Fig. 1B, C), while Zfh1-positive cyst cells dramatically increased in Tj > eIF5 RNAi testes compared with those in the controls (Fig. 1B, D), indicating that dysfunctional cyst cells, mediated by the lack of eIF5, induced excessive accumulation of CySCs and led to the loss of mature cyst cells. Here, EIF5 is linked to cyst.