Sehgal R, Markov Y, Qin C, Meer M, Hadley C, Shadyab AH, Casanova R, Manson JE, Bhatti P, Moore AZ, Crimmins EM, Hagg S, Assimes TL, Whitsel EA, Higgins-Chen AT, Levine M. Systems Age: a single blood methylation test to quantify aging heterogeneity across 11 physiological systems. Nat Aging. 2025 Sep; 5(9):1880-1896.