CXCR4 and pancreatic neoplasm: Moreover, the co-expression of HIF-1α and other important oncogenic products and drug resistance-associated molecules such as K-Ras mutant, which is detected in up to 75–90% of PDAC cases, hedgehog signalling elements, CXCR4, toll-like receptor 4 (TLR4), NF-κB p65, survivin, proliferating cell nuclear antigen and VEGF has also been detected in PDAC tissue specimens from patients and pancreatic cancer cell lines [118, 280, 282–288].