On 2013 Oct 28, DAVID SANDERS commented:

Identical Env deletions to those described in this article ("The Env truncated at 616 exhibits maximum fusogenicity in cell-to-cell fusion assay. By comparison, full tail Env (632) and the Env truncated to residue 601 mediated fusion at 40%.") are analyzed in Taylor GM, 2003, which is not cited by this article and contains an alternative hypothesis that there is a trimeric coiled coil in the cytoplasmic domain. This hypothesis has gained recent support. Löving R, 2012

Analysis of the effects of Env mutations in Li M, 2001, Yang C, 1997, and Taylor GM, 2003, which is inconsistent with the hypothesis proposed by the authors of this Exp Mol Pathol article, was also ignored by them.

On 2013 Oct 28, DAVID SANDERS commented:

Identical Env deletions to those described in this article ("The Env truncated at 616 exhibits maximum fusogenicity in cell-to-cell fusion assay. By comparison, full tail Env (632) and the Env truncated to residue 601 mediated fusion at 40%.") are analyzed in Taylor GM, 2003, which is not cited by this article and contains an alternative hypothesis that there is a trimeric coiled coil in the cytoplasmic domain. This hypothesis has gained recent support. Löving R, 2012

Analysis of the effects of Env mutations in Li M, 2001, Yang C, 1997, and Taylor GM, 2003, which is inconsistent with the hypothesis proposed by the authors of this Exp Mol Pathol article, was also ignored by them.