While our plasma data differ from the serum data generated by McGrath et al. [15] who observed a significant decrease in TRAIL concentration in the serum from IPF patients when compared to normal subjects, the results from both studies suggest that there might be a lack of TRAIL and TRAIL-mediated effects in the lungs of IPF patients. The gene discussed is TNFSF10; the disease is idiopathic pulmonary fibrosis.