Fig. 1.

Hypothesis of cellular senescence in CF airways. Signal transduction pathways are commonly activated in CF epithelial cells (left) and are hypothesized to be involved in senescent CF cells (right) upon defective senescence immunosurveillance. CF senescent cells might promote further recruitment of neutrophils (PMNs) into the bronchial lumen through the activation of ROS and mitochondrial stress signalling, which in turn increase SASP release, worsening the lung inflammatory process and activating pro-tumoural pathways. DDR, DNA damage response; SAHF, senescence-associated heterochromatin foci