Tormin et al. [43] reported increased serum concentrations of soluble factors, such as C-C Motif Chemokine Ligand 5 (CCL5), C-X-C Motif Chemokine Ligand 8 (CXCL8), Interleukin 1 receptor antagonist (IL-1ra), IL-4, IL-9 and platelet-derived growth factor (PDGF), in patients with late RHD. This evidence concerns the gene IL4 and rheumatic heart disease.