ESR1 and neoplasm: A recent elegant study using pregnancy as a condition depicted that raised endogenous plasma estradiol levels could upregulate myelopoiesis, mobilize MDSCs from the bone marrow into the spleen and tumor beds, potentiate the immunosuppressive function of GrMDSCs through ERα and thereby enabled the progression of the ERα negative cervical tumors (Kozasa et al., 2019).