Using primary tumor tissue from patients in the AZURE study, we showed that a novel composite biomarker comprising the proteins CAPG and GIPC1 was prognostic for developing bone metastasis (HR = 4.5, 95% CI = 2.1 to 9.8, P < .001) and predicted response to zoledronate (P = .008) (21). Here, GIPC1 is linked to bone metastasis.