CASP3 and esophageal squamous cell carcinoma: For EC, a natural compound named periplocin (CPP) alone or in combination with TRAIL was found to dose-dependently increase the expression of DR4/DR5, FADD and cleaved caspase-3 by inhibiting FoxP3, inducing apoptosis of ESCC cells and making ESCC cells more susceptible to TRAIL-induced apoptosis 80.