ABCG2 and amyotrophic lateral sclerosis: Notably, no significant change to P-gp and Bcrp were identified in C9 BMECs compared to WT BMECs, while overexpression for P-gp and Bcrp has been observed in SOD1G93A mice (brain cortex and spinal cord) and postmortem ALS human tissues (spinal cord) [7].