a, Relationship of burden of indels per cell with age. The points represent individual colonies (n = 632) and are coloured by smoking status. The black line represents the fitted effect of age on indel burden, which was estimated from LME models after correction for smoking status and within-patient correlation structure. The blue shaded area represents the 95% CI for the fitted line. b, Stacked bar plot showing the distribution of colonies with 0–7 copy-number changes and structural variants across the 16 subjects. c, Three examples of chromoplexy in normal bronchial cells. Structural variants are shown as coloured arcs that join two positions in the genome around the circumference. The instances of chromoplexy all consist of three translocations (purple). d, An example of chromothripsis in a cell from an 11-month old child. The plot on the right shows the copy number of genomic windows in the relevant region of chromosome 1 (black points); the lines and arcs denote the positions of observed structural variants.