Integrin α6 is up-regulated in colon cancer cells and undergoes a shift towards the α6A variant. (A) Quantitative RT-PCR of total α6 subunit mRNA in patient matched resection margins (RM) and corresponding primary tumors (Tu). Mean ± SEM. *: p = 0.025, n = 21, paired t-test. Representative competitive RT-PCR of the α6A and α6B variants (B) and (C) ratio of α6B/α6A transcript levels in patient matched RM and primary tumors of the human colon. Mean ± SEM. *: p = 0.05, n = 21, paired t-test. (D) Dot graphs of the individual α6B/α6A ratios showing a sharp decrease in 17 (grey) of the 21 paired samples analyzed.