VEGF-activated VEGFR-2 plays important roles in mediating the formation of new blood vessels under various pathological conditions and processes, including wound healing, rheumatoid arthritis (RA), diabetic retinopathy (DR), Alzheimer’s disease (AD), small vessel disease, coronary heart disease (CHD), and cancer owing to its complicated molecular and structural characteristics. This evidence concerns the gene KDR and rheumatoid arthritis.