GRK3 and neoplasm: The specificity of LD2 targeting GRK3 was further confirmed when treating MKN45-GRK3 OE cells and control cells using LD2 at different dosage and found that LD2 significantly suppressed tumor cell growth in MKN45-GRK3 OE cells, but no effects in MKN45-GFP control cells (Supplementary Fig. 4A).