“…SSCs are male germline stem cells with indefinite self-renewal ability ( Hofmann, 2008 ; Luo et al, 2009 ; Kanatsu-Shinohara and Shinohara, 2013 ) and are unipotent with respect to their differentiating into sperm through spermatogenesis in seminiferous tubule in the testis ( Aponte et al, 2005 ; Luo et al, 2009 ; Lee et al, 2013 ). Simultaneously, SSCs can acquire pluripotency differentiating into three germ-layer cells by external specific stimulation ( Guan et al, 2006 ; Simon et al, 2010 ; Lim et al, 2013 ) and produce transgenic sperms by introducing target genes into cells ( Nagano et al, 2001 ; Lavitrano et al, 2006; de Barros et al, 2012 ). Accordingly, they serve as a useful tool for understanding spermatogenesis ( Oatley and Brinster, 2008 ; Phillips et al, 2010 ; Kanatsu-Shinohara and Shinohara, 2013 ), preserving male reproduction ( Phillips et al, 2010 ), overcoming male infertility ( Kubota and Brinster, 2006 ; Vlajković et al, 2012 ), conducting patient-specific cell therapy ( Daley and Scadden, 2008 ; Vlajković et al, 2012 ), and producing transgenic animals ( de Barros et al, 2012 ).…”