Normal human physiology is in a dynamic state. Steroid hormone
receptors are naturally scavenged by the body's well regulated systems that keep receptors and ligands in balance.
The receptors that are not met by the ligand also undergo a constant turnover. New ones are continuously generated as long as the body is in good health and there is no disease process like a hormonal
imbalance that affects the number of these receptors expressed on nuclei.
There are many 'orphan' receptors whose ligands have not yet been discovered