MMP9 and cancer: In the ‘pathways in cancer (KEGG)’ gene set, we found another group of known c-JUN targets, i.e. Il6, Lamb3, Lamc2, Mmp1 and Mmp9[14], that are strongly activated for the conditions of ‘engineered human skin’ (GSE 17539) [18] and ‘low dose treatment of 5-aza-2-deoxycytidine on an non-small cell lung cancer cell line’ (GSE 6695) [19] (Additional file 1: Figure S2b).