APOB and abetalipoproteinemia: The vacuolated appearance of the neonatal enterocytes of Trpml3−/−;Trpml1−/− mice is strikingly similar to that of enterocytes from patients suffering abetalipoproteinemia [29] and mutant mice lacking apolipoprotein B [30], in which a deficiency in chylomicron formation results in massive lipid accumulation in the enterocytes.