Great to see APOBECs in the news! My colleagues and I have been working on solving the structures of these proteins for the last 5 years and more. If HNers have any questions, I'll try answering to the best of my knowledge.
The fundamentals of activating APOBECs are being worked out by multiple groups across the world. That said, one phrase you'll always read around the APOBEC3 sub-family of proteins (responsible for the anti-HIV effect), is "double-edged sword". The biggest risk, with (cytidine deaminase) enzymes that act on DNA, thereby changing the fundamental genetic code, is causing cancer. More recently, APOBEC3B (no anti-HIV effect, but same sub-family), was shown to have extremely strong correlation with breast cancer[0]! The emerging therapeutic field involving APOBECs will require highly specific targeting of activators(anti-HIV) as well as inhibitors(anti-cancer)[1].
