Then, we tested the anti-proliferative effect of RK-019 on multiple GC cell lines and found that it could efficiently inhibit the proliferation of FGFR2-amp GC cell lines, SNU-16 and KATO III, with average IC50 values of 3.96 ± 4.4 nM and 5.45 ± 5.3 nM, respectively. Here, FGFR2 is linked to gastric cancer.