Progesterone receptor membrane component 1—Many tasks for a versatile protein

The protein now called Progesterone Receptor Membrane Component 1 (PGRMC1) has been described independently by many groups in different cellular contexts. As a result it has been given an impressive diversity of names. While this protein was initially described on the basis of a singular property, e.g. expression or steroid binding, its possible physiological roles have only recently been reported. Current evidence supports the perception that PGRMC1 may be involved in sterol metabolism or homeostasis and cell survival. Here, we summarize a few sometimes neglected pieces of evidence from the literature along with unpublished findings on the properties and functions of PGRMC1.