Following ANGPTL4 induction, protein synthesis is expected followed by protein secretion. The milk with normal levels of FFAs showed no effect on the ANGTL4 protein section, despite a fourfold mRNA induction. However, milk with a moderately increased level of FFA, inducing a sevenfold increase in mRNA, showed a twofold increase in ANGPTL4 protein secretion after 6 h incubation. Surprisingly, a further increased FFA level accompanied by a twelvefold mRNA induction slightly decreased the protein secretion compared with that induced by the moderately increased FFA level. Thus, after 6 h exposure to high FFA levels the protein secretionwas lower than expected but if cells were left in pure cell culture medium for another 18 h after the treatment, a protein excretion level comparable with that of the moderate FFA inductionwas achieved. Hence, the level of FFAs up-regulates ANGPTL4 gene and protein expression, which is in agreement with previous studies showing that FFAs can up-regulate both the ANGPTL4 gene and the protein secretion in many different cell types (Grootaert et al., 2011; Kersten et al., 2009). Oleic acid and linoleic acid were shown to up-regulate ANGPTL4 gene expression in mouse intestinal cells, and propionate and butyrate to up-regulate ANGPTL4 protein secretion from several human intestinal cell lines (Kersten et al., 2009).