**6.2. cFLIP**

cFLIP is overexpressed in many types of cancers like melanoma, colon lymphoma and thyroid cancer [226]. The CD133+ populations within the T-cell acute leukemia cell line Jurkat and the breast cancer cell line MCF7 were reported to express higher levels of cFLIP, which was associated with TRAIL resistance. The down-regulation of cFLIP using siRNA restored TRAIL signalling in both cell lines resulting in a dramatic reduction in experimental metastases and the loss of CSC self-renewal [227]. This suggests that a combined TRAIL/FLIPi therapy could prevent metastatic disease progression in cancers.
