XAF1 and gastric cancer: A study by Ling et al showed that XAF1 tumor methylation in gastric cancer is linked to decreased survival, with a median DFS of 23.4 months in patients with methylated XAF1, in contrast to a median DFS of 39.6 months in patients with unmethylated XAF1. Correspondingly, patients positive for serum XAF1 methylation had significantly lower DFS than patients negative for serum XAF1 methylation (Ling et al. 2013).