Several previous studies of effusion samples reported that the expression of Ber-EP4 in reactive mesothelial cells was 0-14% and 0-6% of malignant mesothelioma, 83-100% of adenocarcinoma cells, and 0% of squamous cell carcinoma (Robert et al., 2001; Takeshima et al., 2008; Saleh et al., 2009; Huang and Michael., 2014). This evidence concerns the gene EPCAM and adenocarcinoma.