EGR1 and cyst: Possibly, Stra8 can stimulate Sertoli cell proliferation and cyst formation through a yet unknown pathway that may involve germ-to-Sertoli cell signaling, since stra8 crispants also showed reduced levels of egr1, encoding a transcription factor that stimulates Dmrt1 expression in murine Sertoli cells (Lei and Heckert, 2002).