ABCC5 expression is elevated in breast cancer bone metastases. (A) ABCC5 gene expression was found to be significantly overexpressed in breast cancer bone metastases (BMs) compared with primary breast tumors (BTs) that were metastatic to bone by both Agilent microarray analysis (left panel) and RT-qPCR (right panel); *P = 0.002; **P = 0.03. (B) Immunohistochemical (IHC) analysis confirmed that ABCC5 expression was higher in bone metastases (right panels) compared with primary breast tumors (left panels). IHC was performed on frozen sections for all the samples, and the ABCC5 staining intensity is indicated in the lower left corner of each image. Scale bar in the first panel represents 100 μm and applies to all images.