We expressed WNT4 or WNT3A fused to C-terminal BirA biotin ligase in HT1080 WT and porcupine O-acetyltransferase (PORCN)-knockout (PKO) cells (Wnt-responsive fibrosarcoma cell line), and ILC cell line MDA MB 134VI (MM134; Supplementary Fig. S1A–S1C). This evidence concerns the gene PORCN and fibrosarcoma.