FGFR2 and gastric cancer: Genetic or mRNA change in FGFR1-4 accounts for 12%, 13%, 10%, and 9% of GC cases, respectively, and FGFR2 expression demonstrates a positive correlation with its copy number gain/gene amplification, suggesting that copy number aberration partially contributes to overexpression of FGFR2 (p < 0.001, Fig. 1b).