Lin et al. demonstrated that mutations of chromosomal-modifying genes and the ERBB-PIK3CA signaling pathway were important in NPC, directly affecting epigenetic modification and promoting invasion.18 These abnormalities were widely observed in other malignant tumors.23,24 However, in the present study, no mutations of chromosome-modification pathways were detected; additionally, no mutations of RTK cycle pathway-related genes were tested, which may explain why pLELC is less aggressive than NPC. This evidence concerns the gene EGFR and cancer.