We did not observe significant changes in the accumulation of Muc-2 transcripts (not shown), nor differences in the thickness of the mucus layer in the distal colon from PTEN mutant mice and control littermates under physiological conditions, suggesting that the mucus barrier was not the main determinant in the differential response between the two groups of animals to DSS-induced colitis. The gene discussed is MUC2; the disease is colitis.