Decreased DRA mRNA levels in colon and cecum but not ileum of K8−/− mice. The mRNA levels of DRA were determined from mucosal scrapings isolated from ileum (A), cecum (B), and proximal (C) and distal colon (D) of K8+/+, K8+/−, and K8−/− mice (n = 4). DRA mRNA levels were decreased 2- to 4-fold in K8−/− cecum and proximal and distal colon compared with K8+/+ (*P < 0.05, ***P < 0.001).