We implanted DLL4 overexpression and knockdown PDX cell lines subcutaneously into T/B-deficient nude mice to investigate whether DLL4 affects TNBC development in TTN-deficient mice (Fig.S9c-d), and tumor burden was limited by DLL4 expression in PDX1/PDX2 regardless of TTN genotype (Fig.S9e). Here, PDX1 is linked to neoplasm.