A U2OS cells were transiently transfected with the GFP-USP45 or GFP alone. Thirty‐six hours post‐transfection cells were irradiated with UV‐C (150 J/m2) through a micropore filter (lower panels) or left untreated (upper panels). Five minutes post‐irradiation, cells were fixed and co‐immunostained with antibodies recognising cyclobutane pyrimidine dimer (CPD) DNA lesions and GFP. The white arrows indicate co‐localisation between GFP-USP45 and CPD. Scale bar, 10 μm. 