Actually, Richard, they DO now know what this circulating blood element is...it is suPAR.http://www.thekidneydoctor.org/2011/09/commentary-focal-segmental.htmlhttp://renalfellow.blogspot.com/2011/08/supar-breakthrough-in-fsgs.htmlIsn't this fantastic news!!??? This is a very recent discovery, and it is transplant patients with fsgs who will probably benefit first/most. It would be great if a treatment could be created for fsgs patients not yet on dialysis. There's still hope!