**3. Genetic predisposition**

Several studies have demonstrated that GCA is a complex disease, where multiple genes confer susceptibility. In most surveys, the allele HLA-DRB1\*04 has been shown to be related to disease and its severity. [13] More recent studies have implied the role of genetic variants in the evolution of the immune and inflammatory pathways in GCA and its clinical expression. Polymorphisms include the rs20541 (R130Q) polymorphism of the IL-13 gene [14], the rs2779251 in the NOS2 gene, the rs1885657 and the rs2010963 in the VEGF gene [15] and, also, the TLR-4 (+896A/G) gene. [16]
