MTTP and cystic fibrosis: We find that enzymes of re-esterification (monoacylglycerol acyltransferase and diacylglycerol acyltransferase), and the rate-limiting enzyme of chylomicron synthesis (microsomal triglyceride transfer protein) are all intact in both the duodenum and ileum of CF mice and comparable to non-CF mice (Supplemental Fig. S3).