1. Negative Feedback Mechanisms and Their Roles during Pattern Formation
Norbert Perrimon, Andrew P McMahon 
Cell 
Volume 97, Issue 1, Pages (April 1999)
DOI: /S (00)

2. Figure 1
Multiple Levels of Control of a Signaling Pathway by Negative Feedback Mechanisms
Molecules that act in a negative feedback mechanism are indicated. 1, 2, and n refer to the various molecules that transduce the signal from the membrane to the nucleus.
Cell  , 13-16DOI: ( /S (00) )