One patient-related parameter, the ECOG performance status at the first onset of metastasis; three tumor-related parameters including WHO histology, bone metastasis and peritoneal metastasis or malignant ascites in the first episode of metastasis; four laboratory-related parameters including HGB concentration, ALB level, LDH level, CEA level; and one treatment-related parameter, palliative chemotherapy were included. This evidence concerns the gene CYGB and bone metastasis.