Representative images from phospho-RTK (left panel) and phospho-kinase (right panel) arrays from chordoma cases 18, 17b, 20 and 21. The EGFR and EPHB2 TK are frequently activated and downstream RTK signaling intermediates are activated consistently in chordomas. Each kinase is spotted in duplicate. The pairs of dots in each corner are positive controls. Each pair of the most positive kinase dots is denoted by a numeral, with the identity of the corresponding kinases listed as follows: 1) EGFR, 2) CSF1R, 3) MSPR, 4) PDGFRB, 5) FGFR3, 6) EPHB2, 7) HER2, 8) TOR, 9) AKT, 10) TP53, 11) RSK1/2/3, 12) S6K, 13) CREB, 14) YES, 15) MSK1/2, 16) RSK1/2, 17) eNOS.