An in vitro study, for instance, revealed that lipid-based additives such as Peceol and Gelucire 44/14, both approved as GRAS, inhibit the PgP-mediated efflux in human colon adenocarcinoma cells (Caco-2) by decreasing the PgP-protein expression (20). This evidence concerns the gene PGP and colon adenocarcinoma.