Approximately 95% of LGSOC patients have tumor ER expression and 50% have PR expression, which represents a potential therapeutic target.[24] Gershenson et al[54] found that the PFS of stage II to IV LGSOC patients receiving hormone maintenance therapy after the initial treatment was significantly longer than that of patients in the observation group (26.4 months vs 64.9 months). The gene discussed is ESR1; the disease is neoplasm.