To verify that TRAIL-ATNC targets the TRAIL receptor on the surface of tumor cells and mediates programed cell death, we first examined the expression of the TRAIL death receptors, DR4 and DR5, in A549 and H1703 human lung cancer cells, and MDA-MB-231 human breast cancer cells (sFig. 10A-C), all of which are known to express higher amounts of DR4/DR5 than DcR1/DcR257,58. This evidence concerns the gene TNFRSF10C and breast cancer.