Breast cancer remains a global health challenge with varied prognoses despite treatment advancements. Therefore, this study explores the pseudogene MGAT4EP as a potential biomarker and therapeutic target in breast cancer. Using TCGA data and bioinformatics, MGAT4EP was identified as significantly overexpressed in breast cancer tissues and associated with poor prognosis. Multivariate Cox regression confirmed MGAT4EP as important prognostic factor. A clinical prediction model based on MGAT4EP expression showed high accuracy for 1-, 3-, and 5-year survival rates and was translated into a nomogram for clinical application. Functional studies revealed that silencing MGAT4EP