However, we show here that Ch25h−/− mice are not protected against iBALT‐independent emphysema development and that B cell‐deficient mice upregulate oxysterol synthesizing enzymes after chronic CS exposure similar to their wild‐type counterparts, yet are still protected against COPD development (John‐Schuster et al, 2014). Here, CH25H is linked to chronic obstructive pulmonary disease.