E2F1 and neoplasm: Functional studies on B-cell lymphomas and mouse colonocytes have shown that overexpression of miR-17-92 on an elevated c-myc background, promotes tumour growth by targeting E2F1 and increased angiogenesis by targeting thrombospondin-1 (TSP1) and connective tissue growth factor (CTGF; He et al, 2005; O'Donnell et al, 2005; Dews et al, 2006).