ERBB2 and chordoma: Along this line, Weinberger and co-workers found EGFR and HER2 expression in respectively 12 (100%) and seven (58%) out of 12 chordomas, using IHC on tissue micro-arrays (TMA), while Shalaby and colleagues showed EGFR expression and activation in respectively 69% (79/114) and 50% (56/115) of chordoma cases by the same technique, and while Fasig and co-authors reported EGFR activation in nine out of 21 (43%) cases [12,15,16].