EGFR and non-small cell lung carcinoma: For example, a microfluidic chip-based CTC technology has been developed, which isolates relatively high numbers of CTCs and can be used to non-invasively detect drug-sensitive and -resistant epidermal growth factor receptor (EGFR) mutations from non-small cell lung cancer (NSCLC) patients (Nagrath et al, 2007; Maheswaran et al, 2008).