Therefore, the high cellular concentration of Mg2+ in in vitro culture system (approximately 4 mM) would greatly dampen any effects elicited by lithium [48], and it is not unexpected that lithium would exert better GSK3β inhibition effect in vivo than in vitro. Our study using lithium chloride to target GSK3β in a murine xenograft model of endometrial cancer suggests potential efficacy as an antineoplastic. Here, GSK3B is linked to endometrial cancer.