Thymus shrinks with age!!! around age 65 -75 its hard even find?
If there is not thymus... than there is no T cell maturation... part of immune system is no longer working!!!
Crazy! it starts to slowly shrink in adolescents.
Read up more on Thymus - how to stimulate again.
Good blog - about the thymus
http://joshmitteldorf.scienceblog.com/2013/03/03/halting-thymic-involution/
Someone experimented on himself and published it - gave himself growth hormones... increased the thymus by alot.
http://online.liebertpub.com/doi/abs/10.1089/109454503322733063