APOE and idiopathic interstitial pneumonia: In addition, a study performed in a bleomycin-induced IPF model on ApoE−/− and WT mice provided evidence that ApoE plays a beneficial role in facilitating fibrosis resolution, and the mice were evaluated eight weeks after treatment with saline or bleomycin, a period in which the resolution of fibrosis in bleomycin-treated lungs has been observed.