This is important as it provides a mechanism which expands the influence of the pRb-E2F pathway from its well established role in cell cycle progression, to encompass cell migration and invasion; specifically, tumour cells which harbour defective pRb and enhanced E2F1 activity through PRMT5 would, in addition to the impact on proliferation, exhibit enhanced invasive properties by virtue of increased expression of genes such as cortactin/CTTN. This evidence concerns the gene CTTN and neoplasm.