ESR1 and COVID-19: The objective of this research was to analyze the expression of Estrogen Receptor α (ERα), Estrogen Receptor β (ERβ), G Protein-Coupled Estrogen Receptor (GPER), and the Angiotensin-Converting Enzyme 2 (ACE2) receptor, as well as their relationship with the viral load of SARS-CoV-2 and serum cytokine levels in three demographic groups of unvaccinated individuals diagnosed with COVID-19: premenopausal women, postmenopausal women, and men.