Based on prior analysis of the regression of p16 expression by chronological age, this mean difference of 1.3 log2 units (95% CI 0.79–1.9, p < 0.001) between the SCD and comparator groups may be as much as 43 years (95% CI 23–63 years) of increased biological aging (Figure 1A) [17]. This evidence concerns the gene CDKN2A and Schnyder corneal dystrophy.