FAS and esophageal squamous cell carcinoma: The Spearman correlation coefficients revealed that expression of FasL and Fas, FasL and caspase 10, FADD and caspase 8, FADD and caspase 10, and caspases 8 and 10 in ESCC were strongly associated (r ≥ 0.28, p < 0.0001).