The formation of monocyte–platelet aggregate (MPA) induces the phenotypic conversion of monocytes into proinflammatory monocytes via the platelet release of transforming growth factor (TGF)β1, resulting in inflammation (interleukin‐1β, tissue necrotic factor‐α) and vasculopathy in Kawasaki disease (KD). This evidence concerns the gene TGFB1 and vascular disorder.