Prognostic significance of the MRP2 expression was also widely discussed in other malignancies, such as esophageal squamous cell carcinoma [32], medullary thyroid carcinoma [33], pancreatic cancer [34], squamous cell carcinoma of the head and neck [35], lung cancer [36, 37], hepatocellular [38] and cholangiocellular carcinoma [39]. This evidence concerns the gene ABCC2 and lung cancer.