Protein expression levels of FFAR4 associated negatively with fasting TG and AUC(TG)0–180 min in patients with type 2 diabetes mellitus (r = −0.62 and r = −0.59, respectively, both p < 0.01), but not in CON (r = 0.15, p = 0.48 and r = 0.25, p = 0.26, respectively). Here, FFAR4 is linked to type 2 diabetes mellitus.