BCL2L1 and malignant glioma: Because experimental work with glial cell tumors indicates that TWEAK induces the expression of the anti-apoptotic proteins Bcl-xL and Bcl-w, we used RT-PCR analysis to study Bcl-xL and Bcl-w mRNA expression in Wt cerebral cortical neurons incubated with TWEAK 1, 3, 6 or 24 hours.