PGRMC1 and cancer: Cancer cells are known to have up-regulated iron uptake,(31) leading to increased heme biosynthesis.(32) It has been reported that PGRMC1 interacts with ferrochelatase (FECH), the terminal enzyme for heme biosynthesis, and regulates its activity by controlling heme release.(33) In addition, a recent report shows that PGRMC1 up-regulates hepcidin expression, which is a peptide hormone produced by hepatocytes that plays a role in iron homeostasis.(34) However, the exact mechanism by which PGRMC1 regulates hepcidin expression remains unclear.