PEITC sensitizes the TRAIL pathway in hCSC apoptosis. A) Representative immunoblot and densitometric analysis (n = 3) of cPARP levels in hCSCs after concentration- dependent PEITC exposure in the presence/absence of TRAIL (10 ng/ml) and TNFα (10 ng/ml), normalized to housekeeping β-actin expression levels. PEITC independently induced as well as synergized TRAIL induction of cPARP in hCSCs. B) A quantitative bar graph illustrating individual effects as well as synergism between 10 μM PEITC and TRAIL (10 ng/ml) in sensitizing TRAIL-mediated apoptosis (n = 3). C) Representative FACS scatter plots of data shown in B with annexin V–FITC/propidium iodide staining, confirming individual effects as well as synergism between PEITC (10 μM) and TRAIL (10 ng/ml) in sensitizing TRAIL- mediated apoptosis (i–iv). All data represent means ± SEM, and significance was determined by comparing with naïve control or as indicated, *p ≤ 0.05, **p ≤ 0.01, ***p ≤ 0.001.