a new proteomic clock from Adiv Johnson and the Stanford lab of Benoit Lehalier a new methylation clock developed with “deep learning” algorithms by an international group from Hong Kong the advanced methylation clock developed by Morgan Levine, Len Guarente, and Elysium Health Prelude Aging clocks = algorithms that compute biological age from a set of measurable markers. Why are they interesting to us? And what makes one better than another? The human lifespan is too long for us to do experiments with anti-aging interventions and then evaluate the results based on whether our subjects live longer. The usefulness of an aging clock is that it allows us to quickly evaluate the effects on aging of an intervention, so we can learn from the experiment and move on to try a variant, or something different.