FGFR1 and neoplasm: Combination treatment with ARS-1620 and AZD4547, an FGFR1 inhibitor, for 3 days showed cytotoxic effects on H358 cells that were comparable to those of ARS-1620 treatment alone (Figure 1(d)); however, this treatment exhibited an enhanced tumor cell-killing effect on H23 and Calu-1 cells (Figures 1(e) and 1(f)).