WNT4 and neoplasm: Due to the limited biological significance of results obtained with established cell lines, we additionally tested the effects of WNT4 on primary HGSC tumour cells directly obtained from ascites, which confirmed our findings with OVCAR4 cells, as CM from WNT4‐overexpressing cells induced stronger tumour cell migration (Figures 6D and S9B) and adhesion to mesothelial cells (Figures 6G and S11B) compared to CM from control transfected cells .