FAQ: Why is it called EnGen SpRY Cas9?

The name SpRY is derived from S. pyogenes and the preference for 5´-NRN-3´ over 5´-NYN-3´ PAMs in vivo (R denotes purines (A or G) and Y denotes pyrimidines (C or T)). Nonetheless, SpRY Cas9 displays essentially no PAM preference in vitro.