The epiAge test resembles an epigenetic clock. To determine the biological age of the subject, it targets certain methylations on the DNA. DNA methylation is the most important epigenetic change. The body uses it to control whether a gene segment can be read or should remain silent. This is how important bodily functions are regulated. Lifestyle and environmental factors impact the speed of changes and even their potential reversal:
https://www.youtube.com/watch?reload=9&v=Ob9D0QkjTeU