PCSK9 and obesity due to melanocortin 4 receptor deficiency: Our findings indicated that fish oil feeding reduced the expression of rno-miR-29c and increased the expression of rno-miR-328 and rno-miR-30d in FOH group, and target regulated the expression of Per3, Pcsk9, and Socs1, respectively. Per3 is a critical circadian rhythm gene and associated with obesity and diabetes [58]. Pcsk9 has attracted much attention for its crucial role in LDL receptor degradation and cholesterol metabolism [59]. Socs1 plays an important role in immune responses and takes part in insulin and leptin signaling pathways [60].