KISS1 and nasopharyngeal carcinoma: The RT-PCR analysis revealed that compared with well differentiated nasopharyngeal carcinoma cells, such as CNE-1 cells and HK-1 cells, the mRNA of KISS1 and KISS1R were lowly expressed in poorly differentiated nasopharyngeal carcinoma cells, such as HNE1 cells and 5-8F cells (Figure 1B).