TF expression in cancer cells parallels genetic tumor progression with an impact of K-ras and p53 status. Flow cytometric analysis of surface TF antigen levels present on (A) DLD-1 or (B) HCT116 CRC cells, and their respective sublines created by selective disruption of mutant K-ras or p53 by homologous recombination (+ indicates wild-type allele; mut, mutant allele; del, disrupted allele). Analysis of TF mRNA and protein expression in these cells by (C) Northern and (D) Western blotting. (E) Cell surface TF activity of HCT116 sublines parallels TF antigen expression. Error bars indicate standard deviation.