As revealed in Fig. 4A, B, overexpression of CMTM3 decreased EGFR expression level, p-EGFR and p-STAT3, but no significant differences were observed in p-AKT or p-ERK1/2 in chordoma cells as analyzed in Fig. 4E, F. Moreover, knockdown of CMTM3 increased EGFR expression level, p-EGFR and p-STAT3 as shown in Fig. 4C, D, and analyzed in Fig. 4G, H. To further confirm the above results, we used IHC staining to analyze EGFR expression level. This evidence concerns the gene MAPK3 and chordoma.