SA-β-Gal staining of lung slices from COVID-19 and control patients. (A) SA-β-Gal staining (left) and HE staining (right) of four COVID-19 lungs and one control lung. We only found signs of senescence (blue staining) in lungs from individuals with very short telomeres (<P1), both in structural and immune cells (black arrows). Conversely, staining was weak for a patient with short telomeres and absent for patients with normal TL and in control tissue. (B) overview of detected SA-β-Gal activity within analyzed samples.