Transfections with a reporter plasmid containing the 3' untranslated region of the gene encoding ERα (<i>ESR1</i>) with and without miRNA let-7 mimics or inhibitors or an estrogen response element-driven reporter construct (ERE) construct were conducted.<b>Measurements and Main Results:</b> ERα expression increased in IPF lung tissue, myofibroblasts, or BLM mice.