CTSS and neoplasm: The status of cathepsin expression in the tumor cells or on the recipient site has been modulated by RNA interference, knock-out technology, or overexpression (Berchem et al., 2002; Gondi et al., 2004; Lakka et al., 2004; Li et al., 2005; Alvarez-Diaz et al., 2009; Burden et al., 2009; Ward et al., 2010; Malla et al., 2011; Withana et al., 2012).