In this study, we showed that APCDD1 knockdown increased the expression of CDC25A, LRP6, LEF1 and NKD1, which are confirmed targets of the canonical Wnt pathway in Ewing sarcoma (64–68) (Supplementary Figure S14), implying that APCDD1 might act as a Wnt inhibitor in this cancer. Here, NKD1 is linked to Ewing sarcoma.