cIAP1 and cIAP2, for example, have been shown to be overexpressed in various tumors, including cervical cancer, esophageal squamous cell carcinoma, hepatocarcinoma, medulloblastoma, several forms of lung cancer, pancreatic cancer and many more, as summarized by Dubrez et al. [27]. This evidence concerns the gene BIRC2 and esophageal squamous cell carcinoma.