It is appreciated that age has a modifying effect on the clinical presentations of disorders such as hyperthyroidism and systemic lupus erythematosus. Similarly in EORA, there seems to be a change in the disease phenotype when it is compared to YORA. These differences are significant not only in highlighting the importance of the aging process on the immune system but also because they have medical and therapeutic implications. Improved classification has greatly improved our understanding and treatment of systemic lupus erythematosus, juvenile chronic arthritis, and seronegative spondyloarthropathies. Similarly, appreciating the differences, and similarities, between YORA and EORA should advance the choice of therapeutic options and potentially move closer to defining pathogenesis and origin.