Figure 5A–C shows representative MXRA8 staining in an ER+ tumor, a TNBC, and a HER2+ tumor. Although the amount of MXRA8 staining was variable across primary tumors and metastatic lesions, aggressive tumors like TNBC and HER2+ had significantly higher levels of MXRA8 staining in primary tumors and metastatic lesions compared to less aggressive, ER+ tumors (Figure 5D,E). Here, ESR1 is linked to neoplasm.