EGFR and colonic neoplasm: For example, the relatively low efficacy of vemurafenib/PLX4032 in BRAFV600E colon cancer is mainly attributed to the ability of the tumor cells to rapidly feedback-upregulate epidermal growth factor receptor (EGFR) signaling in response to the BRAFi, which does not occur as effectively in melanoma cells due to their intrinsically low EGFR expression [69].