Ferritin and Serum Iron in a Causal Relationship with Estrogen Receptor-Negative Breast Cancer: a Two-Sample Mendelian Randomization Study

The aim of this study was to explore the causal relationship between different serum iron statuses (ferritin, transferrin, transferrin saturation, and serum iron) and the occurrence of estrogen receptor (ER)-positive or ER-negative breast cancer.