CDH1 and infection: Strikingly, aged ALI monolayers infected with WT Sp showed a near‐complete (87%) dissolution of cell peripheral E‐cadherin from an already diminished level of organization (Figure 4a,b, “Aged; WT”); Δply Sp infection also caused loss of E‐cadherin organization but to a lesser extent than WT Sp infection (Figure 4a,b, “Aged; Δply”).