CLDN1 and neoplasm: Given that our microarray data analysis suggests ~95% of genes are unaffected by RNA integrity, we wished to compare microarray and qPCR data for genes that were apparently unaffected by RNA integrity; DPEP1 and CLDN1 were found to be significantly differentially expressed in our microarray data by all of the five methods used and, in addition, there is strong literature evidence for their differential expression between tumour and normal samples.