Abstract
Breast cancer continues to be a significant global health challenge due to its heterogeneity and propensity for therapeutic resistance. The current tumor, node, and metastasis (TNM) staging and molecular classification systems are limited in capturing the full biological complexity of breast cancer. Myeloid differentiation primary response protein 88 (MyD88), a key adaptor protein in inflammatory signaling pathways, has been implicated in various oncogenic processes. This integrative study combines bulk RNA sequencing (RNA-seq), single-cell RNA sequencing (scRNA-seq), and immunohistochemistry (IHC) to explore the prognostic significance and immunological implications of MyD88 in breast cancer. We discovered that elevated MyD88 expression is associated with improved patient outcomes and is linked to the immunological landscape of breast cancer, including immune cell infiltration and the expression of immune checkpoint genes. Furthermore, our analysis indicates that MyD88 high-expressing tumors are more sensitive to chemotherapeutic agents, suggesting its potential as a predictive biomarker for therapeutic response. A nomogram incorporating MyD88 expression with other clinical variables was developed to estimate survival probabilities, enhancing the model's predictive accuracy. Our findings highlight MyD88 as a promising candidate for personalized medicine approaches in breast cancer, warranting further investigation into its mechanistic role and therapeutic potential.