Yes, IFN may be removed down the road, but if IFN-lambda proves to have similar or better efficacy with reduced side effects, why remove IFN when it is known to drive a sustained immune response to the virus? DAAs have side effects also, and efficacy synergy may result in side effect synergy. The only rationale for using multiple DAAs would be if they can shorten the time on therapy. Yoda began dismissing IFN-lambda as a viable option in HCV because DAA combos were entering ph1/2 trials and his rationale was that by the time lambda hit the market, DAA combos would dominate. Two years later, lambda is completing ph2 trials with plans to enter ph3 mid-2011 and we have yet to see a DAA combo succeed. That may change, but the clock is ticking.