 Tumor samples originating from clinically considered multiple or multifocal primary lung cancer patients were available for mutational analysis. DNA and RNA were extracted from fresh tumor tissue or formalin-fixed, paraffin-embedded FFPE tissue. A series of cancer-related genomic alterations including single nucleotide variations SNVs, short insertions and deletions InDels, copy number variations CNVs and gene rearrangements were identified by Oncomine Comprehensive PanelOCP. High frequency mutations were also identified in blood sample by droplet digital polymerase chain reactionddPCR. 