Indeed, transplantation of Dok-3–deficient bone marrow cells induced tumor invasion in Apc mice (Fig. 2B–D) to an extent similar to that observed in Apc/Dok3 mice (Fig. 1D and E), indicating that Dok-3–deficient non-tumor cells have the potential to induce malignant conversion of benign tumors, namely a previously unknown, stromal cell–induced malignant progression in a spontaneous tumor model. This evidence concerns the gene DOK3 and neoplasm.