The human bile duct cancer cell line RBE was subjected to serum starvation for 8 hours in serum-free medium, including both FGFR2 knockout and wild-type conditions, followed by co-incubation with FGF2 and Pemigatinnb. Cell lysis was conducted using RIPA buffer supplemented with protease and phosphatase inhibitors. The cell lysates were sonicated and centrifuged at 12,000 × g for 15 minutes at 4°C to extract total proteins, and the supernatant containing protein lysates was collected. During this process, magnetic beads pre-bound with WDR5 antibody (AB307664, abcam) and conjugated with agarose (HY-K0202, MCE) were mixed according to the instructions and incubated at room temperature on a rotator for 30 minutes. The beads were washed five times with washing buffer and then mixed with the above-mentioned supernatant, followed by overnight incubation on a rotator at 4°C with gentle shaking at 12 revolutions per minute. After washing, the beads were collected, and the proteins adsorbed on the beads were released by heating at 95°C for 5 minutes. Subsequently, 10% SDS-PAGE gel electrophoresis was performed. For conventional protein mass spectrometry analysis, all gel bands were excised.