The mesothelial cells were negative for carcinoma markers, including Ber-EP4 (Ber-EP4, prediluted; Dako), MOC31 (MOC-31, 1:60; Dako), and Claudin 4 (3E2C1, 1:200; Invitrogen, Waltham, MA, USA). This evidence concerns the gene EPCAM and carcinoma.