GLUL and cancer: Overexpression of GS has been documented in a wide array of cancers, wherein it maintains exogenous Gln independently and promotes the proliferative potential of cancer cells (Listrom et al., 1997; Yuneva et al., 2012; Pissimissis et al., 2009; Shi et al., 2014; Bott et al., 2015; Kung et al., 2011).