Dear Editor,
Early ovarian expression of Newborn oogenesis homeobox (NOBOX),a transcription factor belonging to the homeoprotein class,is decisive for the progression of primordial follicles to the primary follicular stage as demonstrated by the sterility of Nobox-/-female mice (Rajkovic et al.,2004).Consequently,the loss of the Nobox gene causes primary ovarian insufficiency (POI) (Rajkovic et al.,2004) and we have shown that 6.2% of POI cases harbor mutations in the NOBOX gene (Qin et al.,2007;Bouilly et al.,2011).Such a high prevalence of mutations demonstrates that NOBOX is a major autosomal gene involved in POI (Bouilly et al.,2011).However,the exact role of this transcription factor during folliculogenesis is unclear.