On 2017 Aug 09, Jacob H. Hanna commented:

This is the third paper from Smith group describing deriving human transgene free naïve "pluripotent" reset cells. However, in all three papers, the authors have failed to describe whether they are able to generate teratomas from any of the described cell lines. It should be noted that mouse naive pluripotent cells have the intrinsic "self organizing capacity" to enter a formative/primed state after in vivo sub-cutaneous injection into immunodeficient mice and robustly make teratomas within 4-8 weeks. In our opinion, without evidence for teratoma formation competence of such transgene free naive cells they do not qualify to be annotated as pluripotent cells at all (neither naive nor primed). We raise the possibility that the cells being propagated in this study may be more akin to a non-pluripotent pre-iPSC/pre-ESC state. I hope the authors can clearly point out and directly address this critical caveat in their future publications.

On 2017 Aug 09, Jacob H. Hanna commented:

This is the third paper from Smith group describing deriving human transgene free naïve "pluripotent" reset cells. However, in all three papers, the authors have failed to describe whether they are able to generate teratomas from any of the described cell lines. It should be noted that mouse naive pluripotent cells have the intrinsic "self organizing capacity" to enter a formative/primed state after in vivo sub-cutaneous injection into immunodeficient mice and robustly make teratomas within 4-8 weeks. In our opinion, without evidence for teratoma formation competence of such transgene free naive cells they do not qualify to be annotated as pluripotent cells at all (neither naive nor primed). We raise the possibility that the cells being propagated in this study may be more akin to a non-pluripotent pre-iPSC/pre-ESC state. I hope the authors can clearly point out and directly address this critical caveat in their future publications.