The primary mechanism is the epigenetic code, a kind of secondary layer of genetic information that determines how our DNA is used. (sciencedaily.com)
I won't go as far to describe the difference in the S1 primary layer and S2 secondary layers, no that would be too geek, even for me. (tandemtrouble.com)
Given the current state of the Bitcoin Blockchain, it is likely that e-commerce platforms like eBay will only integrate Bitcoin once secondary layer solutions are ready for integration, such as Lightning Network. (links2exchange.net)