COL2A1 and metastatic neoplasm: Public domain databases also showed that COL2A1, COL11A1, COL6A1, COL6A2 and LUM were higher in primary/metastatic tumor than in normal tissue (one-way ANOVA, all P-values less than 0.001), and all six genes were differentially expressed across four molecular subtypes based on hormone receptor (HR) status and human epidermal growth factor receptor II (HER2) status (one-way ANOVA, all P-values less than 0.001).