Abstract: In recent years, with the rapid development of the Next Generation Sequencing, the tumor heterogeneity has attracted widespread attention. It has been clear that heterogeneity in the same patient includes inter-tumor heterogeneity and intra-tumor heterogeneity. The former exists between different tumor lesions, such as primary tumor and metastatic tumor, and the latter occurs in different cancer cells. Tumor heterogeneity represents the ongoing challenge in the field of cancer treatment and brings great difficulty for the precision medicine. Therefore, it is possible to achieve accurate diagnosis and therapy for tumor patients by detecting the subclone of tumors and adjusting the treatment plan in time.

Key words: Neoplasms, Genetic heterogeneity, Precision medicine