PCDH20 and nasopharyngeal carcinoma: PCDH20 expression was detected in normal lung and nasopharyngeal tissues, but was silenced or downregulated in non-small cell lung cancer and nasopharyngeal cell lines (Imoto et al., 2006; Chen et al., 2015); the same was also observed in nasopharyngeal carcinoma tissues (Chen et al., 2015).