Similarly, the result of TUNEL assay showed that the number of TUNEL-positive staining of YES-2, KYSE-150 and KYSE-510 ESCC cells treated with CPP (100 ng/ml) and TRAIL (1 μg/ml) were all much higher than cells treated with CPP or TRAIL alone (Fig. 2b and Additional file 1: Figure S2B), which is consistent with the observed activity in proliferation assay. Here, TNFSF10 is linked to esophageal squamous cell carcinoma.