Been following the Radon Spa thread as well. Interesting high-level similarity to LDN?

I'm not up on the immune system chemicals as many of you are but seems the Radon treatment also "adjusts" the immune system and increases endorphins.

"Moreover the therapy enhanced concanavalin A (ConA)-induced mitogen response and increased the percentage of CD4 positive cells, which is the marker of helper T cells, and decreased the percentage of CD8 positive cells, which is the common marker of killer T cells and suppressor T cells, in the white blood cell differentiation antigen (CD8/CD4) assay. Furthermore, the therapy increased the levels of alpha atrial natriuretic polypeptide (alpha ANP), beta endorphin, adrenocorticotropic hormone (ACTH), insulin and glucose-6-phosphate dehydrogenase (G-6-PDH), and it decreased the vasopression level."

From: http://www.ncbi.nlm.nih.gov/pubmed/15133294