Phosphorylation of Smad2/3 at Specific Linker Threonine Indicates Slow-Cycling Intestinal Stem-Like Cells Before Reentry to Cell Cycle

Background Quiescent (slow-cycling) and active (rapid-cycling) stem cells are demonstrated in small intestines. We have identified significant expression of Smad2/3, phosphorylated at specific linker threonine residues (pSmad2/3L-Thr), in murine stomach, and suggested these cells are epithelial stem cells.