Frequency of mLOY (mLRR <−0.15) by age of blood draw in (A) our analytic set of all males in the UK Biobank and (B) by smoking status. Points represent the estimated frequency of mLOY for each age. Error bars in (A) are 95% confidence intervals around the frequency point estimates. Plotted curves are estimated from logistic regression models of mLOY with age and age2 as the predictor variables. Abbreviations: mLOY, mosaic loss of the Y chromosome; mLRR, median log2 intensity ratio of the Y chromosome.