PF403 (Figure 1B), reporting an in vitro anti-glioma activity approximately 1000 times higher than CAT3 [8] in human cell lines, is the active metabolite of CAT3 synthesized by esterases in vivo and can penetrate the blood-brain barrier to demonstrate an anti-glioma effect [12,13,14]. Here, SLC7A3 is linked to glioma.