Additional file 1: Table S1. Description of 20 participating cohorts. Table S2: Epigenetic clocks information. Table S3: Sample size stratified by tissue types, array platforms and birth term status for each epigenetic clock. Table S4: Number of missing CpGs for each epigenetic clock in this study. Table S5: CpGs in all epigenetic clocks. Table S6: Comparison of epigenetic clocks across self-reported decent-associated population groups. Table S7: Comparison of epigenetic clocks between sexes. Table S8: Comparison of epigenetic ages across different tissues from the same set of participants.