To examine the role of MIG-6 in CAH and early-stage (I and II) EEC, we first examined levels of MIG-6 in endometrial biopsies from patients with CAH (n = 18) and early-stage (I and II) EEC (n = 53) and controls (n = 11) using immunohistochemistry (Figure 1). The gene discussed is ERRFI1; the disease is congenital adrenal hyperplasia.