PPIB and neoplasm: ITS (Insulin, Transferrin and Selenium), N2 Supplement, B27 Supplement, Epidermal growth factor (EGF) and b-fibroblast growth factors (b-FGF) were major components added in our sphere-formation pelletizing system, we therefore added these supplements to Panc-1 and MIApaca-2 cells separately and found CTD-3252C9.4 expression was down-regulated by bFGF and EGF, which also exist in the tumor microenvironment (Fig. 1D).