CD79A and infection: Indeed, in young adults with stable CF, and in young children with CF experiencing exacerbations there is regional heterogeneity of lung inflammation [42], [43], in patients with COPD there are also important regional differences in secretory IgA associated with the site and nature of airway remodelling, inflammation and potential susceptibility to infection [44], and it is recognised that there are regional differences in the local responses to stress within the lung [45].