Derived from well differentiated invasive esophageal squamous cell carcinoma resected from middle intra-thoracic esophagus of a 64-year-old Japanese man prior to treatment; cell line Established from tumor cells heterotransplanted into athymic mice; described in the literature to be heterotransplantable in athymic mice and to carry p53 mutation and amplification of cERB B, MYC and CYCLIN D1