Figure 1. Expression of p16^INK4a in PBTL is associated with chronologic age.

(A) Comparison of relative p16^INK4a expression in different cell types of the peripheral blood. Error bars indicate standard error of the mean (SEM). (B) Linear relationship between log₂-transformed p16^INK4a mRNA expression and chronological age. Aggregate data from the exploratory and validation cohorts are shown. The correlation coefficients and p-values of individual cohort are shown in Table 1. Dotted lines indicate the 95% confidence intervals (CI) of the fitted line. (C) Expression of p16^INK4a protein increases with chronologic age in a representative subset of patients.