PGRMC1 and neoplasm: The progesterone receptor membrane component 1 (PGRMC1) is a multi-protein complex that can directly bind to heme and associate with cytochrome P450 proteins, the EGFR receptor tyrosine kinase, the RNA-binding protein PAIR-BP1, and other effect proteins so that PGRMC1 is involved in various functions like tumor growth, cholesterol synthesis, and drug metabolism6–9.