PTK2 and neoplasm: Importantly, the sensitizing effect of VS‐4718 on GDC‐0449 was not observed in ESCC/Gli1 S112/T115/S116E cells (GDC‐0449 IC50 level in KYSE410/Gli1 S112/T115/S116E cells was 18.6 ± 1.1 μM; in KYSE510/Gli1 S112/T115/S116E cells, GDC‐0449 IC50 level was 18.43 ± 3.5 μM), indicating that FAK inhibition enhances the ability of HH inhibitor to suppress tumor development in vitro via suppressing the phosphorylation of Gli1 Ser112/Thr115/Ser116 sites (Figure 5A).