In another study, Kapinja et al. used a brain-penetrant mutant IDH1 inhibitor (MRK-A) and explored its antitumor activity on the growth or animal survival of mice bearing either a patient-derived GB10 glioma xenograft or BT142 xenograft and observed a prolongation of the survival only of mice bearing the BT142 glioma [401]. Here, IDH1 is linked to central nervous system cancer.