Secretion of CANT1 and ELISA of human sera. A: A total of 600,000 LNCaP and 400,000 PC-3 cells were seeded in 6-cm dishes, at 70% density; complete medium was washed away and replaced by serum-free medium. Twenty-four hours later, supernatants were cleared from cell debris, and afterward, vesicles were pelleted by ultracentrifugation. Soluble CANT1 was precipitated and analyzed by Western blotting together with lysates from the same cells. B: CANT1 was detected by a sandwich ELISA in 38 serum samples (15 healthy controls and 23 prostate cancer patients). Displayed are box plots of the different groups.