KLK3 and prostate carcinoma: Isosilybin B was also most effective in repressing the topoisomerase IIa promoter: isosilybin B silybin B isosilybin A silybin A. Finally, isosilybin B was also most effective in suppressing prostate-specific antigen (PSA) secretion by LNCaP prostate carcinoma cells: isosilybin B > silybin B > isosilybin A ≈ silybin A. These results were later confirmed and corroborated by Deep et al. [125] using advanced human prostate carcinoma PC3 cells.