SHH and chronic obstructive pulmonary disease: Because airway epithelial cell differentiation is readily analyzable in air–liquid interface cultures and we previously highlighted the involvement of the HH pathway in differentiation with an experimental strategy relying on an antibody targeting SHH (AB5E1), we investigated the global differential transcriptomic signature of the AB5E1-treated cells in the early steps of the differentiation process (ALI7) in AECs isolated from non-COPD individuals with varying smoking histories (Table 2) (Belgacemi et al., 2020).