PERP and colorectal carcinoma: Importantly, well-described pathways associated with CRC progression, such as ‘Wnt signaling’ (DKK, Axin, CCND1), ‘P53 signaling’ (PERP, SERPINB5), and ‘colorectal cancer’, including AKT (CCND1, TSC, Axin, MET) and transforming growth factor (TGF)-β signaling, were also overrepresented in tumorspheres (Fig. 1d) and were thus potential targets for a TIC-directed therapy.