Simultaneously, expression of TJ markers in tumor and normal squamous epithelial tissues revealed from both semiq-RTPCR and qPCR significant (p < 0.001) down regulation of ZO-1 (3.7-fold), CLDN-1 (2.9-fold), CLDN-7 (3.8-fold), OCLN (1.6-fold) and E-cadherin (2.3-fold) transcripts (Figure 3B). This evidence concerns the gene CLDN1 and neoplasm.