The renal effects of tenofovir were associated with blood levels (abstract 603) at the conference. Another presentation (abstract 103) examined a prodrug of tenofovir, GS-7340, in a 10 day monotherapy study. This produg was associated with 88% lower plasma levels of tenofovir than when the currently prescribed prodrug TDF (tenofovir disproxil fumarate) was administered. It was highly potent and is likely to be studied further as an alternative to TDF.