Mechanisms of HIV-1 nucleoside reverse transcriptase inhibitor resistance: is it all figured out?

The mechanistic basis for some examples of HIV-1 NRTI-resistance can be examined using altered incorporation of nucleoside analogs and surveying what is known about the more recently described mechanisms of chain-terminator removal. The complexity of these resistance mechanisms and the interplay with other factors that contribute to NRT1 resistance are only just beginning to be appreciated.