Second, the number of cyst cells, positively stained with both a cyst cell marker, Traffic jam (Tj) (Li et al., 2003), and an early-stage cyst cell marker, Zinc-finger homeodomain protein 1 (Zfh1) (Eun et al., 2014; Issigonis et al., 2009; Leatherman and Dinardo, 2008), was significantly increased in the Set1 KD testes compared with the Ctrl KD testes at the later time points in the time-course experiments (Fig. 1G, Fig. S3). This evidence concerns the gene CTRL and cyst.