Cytoskeletal markers are routinely used to diagnose tumours of unknown origin or poorly differentiated cells.107,108 Expression of CK-7 is strong in epithelial-derived tumours like colorectal cancers,109, , –112 ovarian cancers113,114 and cervical cancers.115 Research with specifically HPV-associated tumours has revealed that CK-7 has a role in viral replication, thus promoting high-risk HPV-associated tumorigenesis.116. The gene discussed is KRT7; the disease is colorectal cancer.