Adhesion of cells to collagen I and integrin α2 expression. Transduced cells were seeded in collagen I coated 96-wells trays and incubated for 30 minutes before attached cells were analyzed using WST-1. Results are presented as mean relative adhesion + SEM of three to four independent experiments. (A) MDA-MB-231 cells expressing shRNAs against TFPI and empty vector control (n = 24, ***p ≤ .001 against pSiRPG). (B) MDA-MB-231 cells expressing shRNAs against TFPIβ and empty vector control (n = 18, ***p < .0001 against pSiRPG). (C) Sum102 cells expressing shRNAs against TFPI and empty vector control (n = 18). Integrin α2 protein levels were measured in the total lysate of MDA-MB-231 cells with TFPI (D) and TFPIβ (E) downregulated, and of (F) Sum102 cells with TFPI downregulated using Western blot analysis. c-Src was used as loading control. One representative experiment of two to three is presented.