text: Antibodies used in primary reaction and working concentrations were as follows: anti-NF (clone 2F11, reacting with 70-, 160-, and 200-kDa proteins, 0.5 g/ml; DAKO) (21), anti-SR4 (clone N-16; the epitope is located at the N-terminus of human SR4, 0.5 g/ml; Santa Cruz Biotechnology, Santa Cruz, CA) (16), and anti-DLX2 (catalog no. ab18188, 0.5 g/ml; Abcam, Tokyo, Japan) (6, 16, 27) as enteric neural stem cell markers, anti-PCNA (clone PC10; DAKO) as a cell proliferating marker that is specifically expressed in cell nuclei during the S phase (3), and anti-cRET (rabbit polyclonal, 2 g/ml; Assay Biotechnology, Sunnyvale, CA) as a neural crest-derived stem cell marker.