Identification of RET gene fusion by exon array analyses in ＂pan-negative＂ lung cancer from never smokers

The incidence of lung cancer from never smokers has increased dramatically in China nowadays. Strikingly, approximately 30% of the lung cancer patients in East Asian population are never smokers [1, 2]. The majority of these patients are females with lung adenocarcinomas [2]. Identification of oncogenic drivers, which the tumors are ＂addicted to＂ and rely on for survival, has signifi- cantly reformed the current strategies for lung cancer treatment in clinic and initiated the era of personalized therapy [3]. Therapeutics specifically targeting EGFR mutations, frequently observed in never smoker patients with lung cancer, have been very helpful in improving the clinical symptoms as well as the progression-free sur- vival [4-6]. Similarly, patients with lung tumors positive for ALK fusions also benefit from ALK-targeted therapy [7, 8].