MuEp and SaDu shared a common gene signature involving an overexpression of COL11A1. In contrast, nonhierarchical clustering revealed a more specific gene expression pattern for AdCy, characterized by overexpression of COL27A1. In situ studies at RNA level indicated that in AdCy, ECM production results from tumour cells and not from cancer-associated fibroblasts as is the case in MuEp and SaDu. Here, COL27A1 is linked to neoplasm.