Moreover, although CD44+/CD24- breast cancer cells have invasive properties, not all breast cancer cells with the CD44+/CD24- phenotype were able to grow as metastatic tumors whereas others showed aggressive metastatic growth.[14] In addition, although some primary tumors were predominantly CD44+, metastases at certain sites lacked any CD44 expression. The gene discussed is CD44; the disease is metastatic neoplasm.