Forced expression of the α6B subunit inhibits intestinal cell proliferation. (A) Forced expression of the α6A and α6B integrin subunits was confirmed by western blot. (B) Quantification of Caco-2/15 cells undergoing S phase entry expressing α6A and α6B vs an empty vector control was assessed by BrdU incorporation. Mean ± SD. *: Statistically significantly different from the A variant, p < 0.01, Tukey's One Way Analysis of Variance (ANOVA).