Our RNA gene expression data (Fig. 1a–c) revealed that drug resistance in both ER-positive MCF7 cells and triple-negative breast cancer (TNBC) MDA-MB-231 cells was accompanied by marked upregulated expression of genes including NUPR1 (nuclear protein 1, also known as COM1, candidate of metastasis), LCN2 (lipocalin 2), and GPX4 (glutathione peroxidase 4), all considered to encode anti-ferroptotic, cell survival proteins [29–35]. The gene discussed is PROS1; the disease is triple-negative breast carcinoma.