STEAP1B (STEAP Family Member 1B) is a protein that belongs to the Six Transmembrane Epithelial Antigen of the Prostate (STEAP) family. It is involved in metalloreduction, specifically the reduction of iron and copper ions. STEAP1B plays a role in regulating cellular iron homeostasis and metabolism, which are essential for many physiological functions. Although its exact role in human health and disease is still being studied, STEAP1B may have important implications for understanding iron-related metabolic pathways.