For example, ER expression, primarily thought to be a distinctive characteristic between Types II and I, is found in 95% of low-grade EEC/Type I but only in 15–50% of Grade 3 EEC/Type I, while more than 50% of serous carcinomas (Type II) actually have ER expression [22]. The gene discussed is ESR1; the disease is exstrophy-epispadias complex.