Steve Horvath

At a glance

• Steve Horvath is a German-American geneticist and biostatistician. He was long a professor at the University of California, Los Angeles (UCLA) and is now a principal investigator at Altos Labs.
• He became world-famous for the Horvath clock (Genome Biology, 2013): a model that estimates the age of almost any tissue from DNA methylation at a few hundred sites in the genome.
• Later clocks were more closely linked to health and mortality, such as PhenoAge (with Morgan Levine) and GrimAge.
• With the Mammalian Methylation Consortium he developed clocks that work across more than a hundred mammal species, suggesting that ageing partly follows a shared biological programme.
• He also developed WGCNA, a widely used method for gene co-expression network analysis, and founded the non-profit Clock Foundation.
• For longevity, his work is central: epigenetic clocks are used to test whether interventions slow biological ageing.
• Takeaway: commercial ‘biological age’ tests vary widely in quality; look at trends over time rather than a single number.