CD4 and sarcoidosis: We examined BAL cells as the inflammatory response is aberrant in sarcoidosis with (a) yet unknown antigen(s) triggering an exuberant although dysfunctional immune response with CD4 + T cells, Tregs, high levels of Th1 cytokines TNF-α, IFNγ, and IL-210,33,34, along with inappropriate counter regulatory responses.