JF, they are already partners in 135+Daclatasvir, but you are right; an outright buyout would not happen unless VRTX fails in all drug development. As I said before, VX-135 and Ribavirin are antagonistic, and didn't give meaningful SVRs, but Daclatasvir is an outstanding NS5A inhibitor and it must be a good partner drug for VX-135. The SVR12 has to be 90% or better for all viral genotypes in a dosing duration of 12 weeks or less, and the combo has to be safe and very well tolerated, if the partnership with Bristol is going to continue. If the combo works out, Vertex should consider buying Daclatasvir from Bristol. Bristol is no longer developing Hep C drugs in order to concentrate on oncology drugs.