SERPINA1 and metastatic neoplasm: Furthermore, SERPINA1, which was differentially expressed in the tamoxifen-resistant luminal A cell lines (being upregulated in MCF-7 Tam1 and downregulated in T-47D Tam1, T-47D Tam2, ZR-75-1 Tam1 and ZR-75-1 Tam2), also changed its expression in the patient samples (being up-regulated in all three metastatic tumors).