CHST4 and gastric cancer: The results indicated that the survival prognosis of GC patients in the high- and low-expression groups for MET, TKTL1, MIOX, and CHST4 did not differ significantly, while the low-expression group for CLDN9 had a better survival prognosis than the high-expression group (Additional file 2: Figure S2-Additional file 6: S6B).