However, systemic administration of recombinant IFNγ (which would simulate the presence of Th1 biology) and monoclonal antibody-mediated neutralization of IL-13 (which would specifically target Th2 responses) failed to demonstrate efficacy in randomized, placebo-controlled trials of patients with IPF (141, 142). Here, IFNG is linked to idiopathic pulmonary fibrosis.