Breast Cancer is the leading cause of cancer-related mortality among women worldwide. Maximum number of cancer cases are reported from Breast cancer globally. Early diagnosis and timely treatment are essential to reduce breast cancer-related mortality. High-throughput transcriptomic profiling leads to the gene expression analysis of to uncover gene sets associated with disease onset, prognosis, and therapeutic response. In the present study, differentially expressed genes (DEGs) between breast tumor tissues and normal samples, between early and late stages from The Cancer Genome Atlas (TCGA) datasets using the TCGAbiolinks package in R, followed by data preparation, grouping, and normalization. Various genes associated with Endoplasmic reticulum (ER) stress were retrieved from the Gene cards and MSigDB. Endoplasmic reticulum stress is a condition arises by disturbance in the protein folding machinery and by accumulation of misfolded and unfolded proteins inside the ER lumen. The ER stress associated genes with differential expression in Breast cancer were analyzed using GEPIA and Human Protein Atlas. The prognostic genes were identified from Human protein atlas datasets. Gene ontology and Functional enrichment analysis were performed. Several ER stress-related genes were upregulated or downregulated in tumors. Enrichment analysis highlighted pathways involved in cell proliferation, unfolded protein response, and PI3K-AKT signaling. This analysis highlights the prognostic significance of ER stress associated genes in breast cancer.

Buddhi Prakash Jain is an Assistant Professor at the Department of Zoology, Mahatma Gandhi Central University, Motihari, Bihar, India. After completing his Master's from the University of Rajasthan. Jaipur, Rajasthan, pursued his doctoral studies at the School of Life Sciences, Jawaharlal Nehru University (JNU), New Delhi, India. His native place is Sawar village in the state of India. His research interests include gene expression regulation and Endoplasmic reticulum stress in cancer. His research group is working on Proteostasis, Endoplasmic Reticulum Stress in cancer, and Neurodegeneration. He is the recipient of several awards, including a gold medal in Master Programme (M.Sc.), EMBO travel award, DST (Department of Science and Technology) Govt of India, Young Scientist travel award, European Association of Cancer Research (EACR) Developmental Researcher award, and has published several papers in reputed international journals and a number of books and book chapters. He has published several books with Elsevier, including Protocols in Biochemistry and Clinical Biochemistry (2020, 2024), Understanding the Cancer: From Basics to Therapeutics (2022), Post-Transcriptional Gene Regulation and Human Diseases (2022), and Techniques and Protocols in Molecular Biology (2025).