AXL and non-small cell lung carcinoma: This pivotal study therefore suggests that Axl can serve as an amplifier of EGFR signalling.18 Moreover, Axl overexpression lead to resistance to cetuximab in models of non-small cell lung cancer and head and neck squamous cell carcinoma.19 Interestingly, in the same study EGFR is shown to positively regulate Axl expression via the MAPK pathway in a positive feedback loop.19