[45] determined that class 2 tumours show positive signatures for progression and include upregulated KPNA2, BIRC5, UBE2C, CDC25B, COL4A1, MSN and COL18A1 as well as downregulated COL4A3BP, MBNL2, NEK1, FABP4 and SKAP2. In addition, KRT20 expression associated with CIS lesions can be found in class 2 tumours. Here, FABP4 is linked to neoplasm.