CTSS and central nervous system cancer: When the levels of cleaved caspase-3 were evaluated, only minimal induction of cleaved caspase-3 in GLUC2 and KR158 spheroids treated with 10 μM lucanthone for 48 hours were observed, indicating that lucanthone may not be inducing apoptosis in these glioma cell lines (Figure S1), as was shown for another autophagy inhibitor, thymoquinone, which induces cathepsin-mediated, but caspase-independent cell death (39).