Why are there no research on thymus

Since most of our symptoms don't align with Heart or lungs problem. And thymus is the most important organ when it comes to immune system. Thymus is also much more active in young people than old one as t cells deplete overtime, might explain why young and fit people suffer much more afterward and with a delayed onset of symptoms than old ones. This gland also interact with pituitary gland, thyroid and other hormones in the body