Although studies carried out in humans suggested that UCP1 gene polymorphisms are associated with the obesity pathogenesis and with the disequilibrium of lipid metabolism [26,27,28,29,30], these insights are not confirmed in other studies carried out on humans [31,32,33], as well as by the findings obtained in the current study, which showed no correlation between the values of UCP1 and the levels of HDLs and LDLs in investigated horses. The gene discussed is UCP1; the disease is obesity disorder.