Nonetheless, further analyses will be needed to assess the involvement of Pf4 or other prophages in the lysis phenotype displayed by the CF strains, as Pf4 and many other Pf prophages, such as Pf1, Pf5 and Pf-LES, are frequently found among clinical isolates (Finnan et al., 2004; Kirov et al., 2007; Manos et al., 2008; Mathee et al., 2008; Winstanley et al., 2009; Fothergill et al., 2012; Knezevic et al., 2015; Ambroa et al., 2020). Here, PF4 is linked to cystic fibrosis.