Real-time RT-PCR survey of CLDN gene expression in normal and neoplastic tissus. Expression data of 13 selected CLDN family members from 24 normal and 24 tumor tissue cDNAs. The dChip software was used to analyze and cluster the data. Clustering of the CLDN genes and the tissues were performed with distances based on 1-rank correlation and the centroid linkage method. Darker shades of red indicate higher CLDN expression.