Trzeciak-Ryczek et al. [11,12] demonstrated that the gene expression of the cytokines interleukin (IL)-6, IL-8, IL-10, TNF-α, TNF-β, IFN-γ, and granulocyte-macrophage colony-stimulating factor was increased in the peripheral blood leukocytes of RHDV-infected rabbits, and the level of expression depended on the course of RHD and affected the survival time of infected rabbits. This evidence concerns the gene IL6 and rheumatic heart disease.