EGFR and glioblastoma: Overexpression of RTKs has been found in a variety of human cancers: EGFR in GBM [62], lung [63], esophageal [64] and thyroid cancer [65]; HER2/ErbB2 in lung [66], bladder [67], breast [68] and gastric cancer [69, 70]; and MET in lung [71] and gastric cancer [72].