Active Rb protein Ab

[Brett Levay-Young]

I've just read an unreferenced comment in a "perspective" article to an
antibody which is supposed to specifically detect the active form of
the retinoblastoma protein (i.e. the under-phosphorylated form).  Can
anyone point me toward a reference/ source for this antibody?  Was the
comment in the article (Am. J. Resp. Cell and Mol. Biol 11:249 if you
care to see it) unreferenced because this antibody is not yet published?
What is the net-wisdom on this topic?

Brett

Brett Levay-Young, Ph.D.
Department of Surgery
University of Minnesota
Box 120 UMHC
Minneapolis, MN  55455
Phone: 612-624-3185
Fax:   612-624-8909
I-net: brett at whamserver.surg.umn.edu