CCN6-deficient cells acquire anchorage-independent growth abilities. (a) Anchorage-independent growth of human mammary epithelial stable cell lines in soft agar. The upper panels show an assay in soft agar; the lower panels show the colony size under a × 100 magnification of the same wells after 3 weeks in culture. Three independent experiments yielded similar results. (b) Bar graph summarizing the results of three independent experiments in soft agar. (c) CCN6 inhibition induced an increase in phosphorylation of insulin-like growth factor-1 receptor (IGF-1R) and insulin receptor substrate-1 (IRS-1). C1 and C2 are two stable CCN6 deficient clones.