RET and lung cancer: Second-generation sequencing showed that the patient had four somatic mutations: a RET KIF5B exon15-RET exon12 fusion (K15:R12, abundance: 2.7%), which was further confirmed by Lung Cancer PCR Multigene Companion Diagnostic Kit (Maifittier TM) (Maijing Gene Medical Technology Co., LTD., Guangzhou, China) (Figure 3G) and ZytoVision in situ hybridization assay (Figure 3H) and telomerase reverse transcriptase (TERT), succinate dehydrogenase A (SDHA) and TRIO gene amplification.