 With respect to bladder cancer, for example, the link between XRCC4 and risk of cancer susceptibility was based on hospital-based case-control histological studies of gene variants of both XRCC4 and XRCC3 and their possible association with risk for urothelial bladder cancer.The linkage with risk for urothelial bladder cancer susceptibility was shown for XRCC4, but not for XRCC3 With regard to breast cancer, the linkage with "increased risk of breast cancer" was based on an examination of functional polymorphisms of the XRCC4 gene carried out in connection with a meta-analysis of five case-control studies .There is also at least one hospital-based case-control histological study indicating that polymorphisms in XRCC4 may have an "influence" on prostate cancer susceptibility.