Beyond the heterogeneity found in CXCR4 expression among ACC metastases among different individuals as shown in Figure 2 and Table 5, the finding of significant nodule-to-nodule heterogeneity in CXCR4 expression among the lesions present at one time in this single patient led us to analyze CXCR4 expression by immunostaining in multiple metastases of ACC resected at various times from four additional patients. The gene discussed is CXCR4; the disease is adrenal cortex carcinoma.