PIK3CA and nasopharyngeal carcinoma: The analysis of the correlation between the KLF4 expression in nasopharyngeal carcinoma and the expression of c-Met and nEGFR, or the correlation between KLF4 expression and H-Ras and PI3K mutations did not identify an association between the cytoplasmic KLF4 expression and the expressions of c-Met and nEGFR and Ras and PI3K mutations.