Nonetheless, a study evaluating co-treatment with BKM120 and TRAIL in lung cancer cell lines, at the same doses as used in our study, examined levels of DR4 and DR5 after treatment with BKM120 for 16 h and saw no change in receptor levels (in fact, a decrease in DR4 levels) (28), in contrast to the clear increase in DR5 expression we observed in human glioma. This evidence concerns the gene TNFSF10 and central nervous system cancer.