CLDN7 and adenoma: And finally, in a study of 26 colorectal adenomas compared to 90 invasive CRCs (stage I-IV) in addition to their lymph node metastases, immunohistochemistry revealed decreased claudin-7 expression in 62% of adenomas and in 80% of cases of colorectal cancers, compared to their adjacent non-neoplastic epithelia [42].