ERBB3 and brain neoplasm: As expected, HER3 was overexpressed in brain samples (Fig. 1f).5,6 No clear difference in endothelin receptor expression between the isogenic BT474-Gluc tumors in brain and MFP was seen (Fig. 1f).5 However, we observed differential expression of ETA and ETB between BT474-Gluc and MDA-MB-361-Gluc brain tumors.