CD44 and gastric cancer: Supplementary Table 2 shows the top 10 most cited co-cited references. “Identification of gastric cancer stem cells using the cell surface marker CD44” (6) in Stem Cells had the highest number of citations (n = 380), followed by “Lgr5 (+ve) stem cells drive self - renewal in the stomach and build long - lived gastric units in vitro” (7) in Cell Stem Cell, followed by “Global cancer statistics” (8) in CA Cancer J Clin. A co-cited reference network mapping was also constructed for references with ≥50 co-citations (Figure 10).