To determine if the inflammatory process observed in Atg4b-/- mice after tunicamycin-induced ER stress could progress to pulmonary fibrosis, WT and Atg4b-/- mice were treated with a single intratracheal dose of tunicamycin or vehicle control and lungs were harvested at 21 days post-instillation (fibrotic phase). Here, ATG4B is linked to pulmonary fibrosis.