CD4 and sarcoidosis: Contrastingly, PPAR-γ is deficient in alveolar macrophages of those with chronic active sarcoidosis and both PPAR-α and PPAR-γ are significantly under-expressed in peripheral blood and bronchoalveolar lavage fluid derived CD4+ T-cells of those with the non-Löfgren phenotype, likely contributing to the intense Th1 responses observed in the disease (84, 86).