CASP3 and pancreatic ductal adenocarcinoma: Aberrant caspase-3 protein expression has been extensively studied in many cancers, such as gastric cancer [12], hepatocellular carcinoma [13], prostate carcinoma [14], glioblastoma [15], melanoma [16], breast carcinoma [17], pancreatic ductal carcinoma [18], non-small cell lung carcinoma [19], and oral SCC [20–22].