BAAT and idiopathic pulmonary fibrosis: Second, although BAAT is expressed in the lung, its baseline levels are very low, raising doubts about whether the resulting conjugated bile acids are sufficient to exert meaningful physiological effects.Therefore, future studies should focus on clarifying the functional status of BAAT in lung tissue: examining BAAT protein expression via immunohistochemistry or Western blotting; evaluating its enzymatic activity using lung tissue homogenates; and comparing the ratios of conjugated to free bile acids in IPF and control lung tissues using metabolomic approaches.