{
 "approved_by_author": "\u231b",
 "citation": "Lu, A. T., et al. \u201cDNA methylation GrimAge version 2.\u201d Aging 14(23): 9484\u20139549 (2022).",
 "citations": 291,
 "citations_date": "2026-07-05",
 "clock_name": "grimage2packyrs",
 "data_type": "DNA methylation",
 "doi": "https://doi.org/10.18632/aging.204434",
 "journal": "Aging",
 "last_author": "Steve Horvath",
 "model_type": "elastic net regression",
 "n_features": 173,
 "notes": "DNAm PACKYRS is a methylation surrogate for cumulative smoking exposure and a GrimAge component.",
 "platform": [
  "Illumina 450K"
 ],
 "population": "older adults",
 "postprocess": "cox_to_years",
 "predicts": [
  "smoking exposure"
 ],
 "reference_values": true,
 "research_only": true,
 "species": "Homo sapiens",
 "tissue": [
  "whole blood"
 ],
 "training_target": [
  "smoking exposure"
 ],
 "unit": [
  "pack-years"
 ],
 "version": "0.5.0",
 "year": 2022
}