ESR1 and disease of peritoneum: In 2018, Stover et al., using targeted NGS, detected a Y537S ESR1 mutation in one patient with LGSOC; this particular patient developed a single site of progressive disease in an abdominal wall nodule and maintained stable low-volume peritoneal disease during endocrine therapy for almost five years, but later presented progressive disease after a durable response to hormonal therapy [32].