ABCG2 and glioblastoma: In contrast, one study found that the human EGFR inhibitor LRIG1 can regulate quiescent neural stem cells’ responsiveness to EGFR signaling (prompting NSC exit from quiescence) [53], while another reported that LRIG1 can reverse the course of multi-drug resistance by suppressing ABCB1 and ABCG2 [54] in glioblastoma cell lines.