CASP3 and Merkel cell skin cancer: Exposure to combination of celecoxib (50 μM) and orlistat (100 μM) for 24 h resulted in apoptosis (TUNEL assay) in colonoid cultures (Fig. 3h) and much higher CHOP and cleaved caspase 3 levels in explant tissue from MCC compared to NMCC, suggesting their susceptibility to ERS aggravation and ERS-mediated apoptosis (Fig. 3i).