1. Biomarkers and Photodynamic Therapy for Barrett's Esophagus: Time to FISH or Cut Bait? 
Stuart Jon Spechler, Rhonda F. Souza 
Gastroenterology 
Volume 135, Issue 2, Pages (August 2008)
DOI: /j.gastro
Copyright © 2008 AGA Institute Terms and Conditions

2. Figure 1
Retinoblastoma (Rb) protein controls progression from G1 to S phase of the cell cycle by blocking at the restriction (R) point. Cyclins in complex with cyclin-dependent kinases (cdK) can phosphorylate and inactive Rb, allowing cells to advance through the R point into S phase. This Rb phosphorylation can be inhibited by both p16 and p53. High levels of p53 also can trigger apoptosis, and p14ARF can increase levels of p53. Note how loss of p16 and p14ARF can enhance entry into S phase, where the cells might be less susceptible to injury by PDT.
Gastroenterology  , DOI: ( /j.gastro )
Copyright © 2008 AGA Institute Terms and Conditions