MADM allows visualization of early lesions and detailed tumor organization.

<p>(A) A representative brain section from a MADM-generated medulloblastoma. The GFP-labeling of mutant cells amidst sparse background labeling of granule neurons clearly identifies early lesion sites consisting of only hundreds to thousands of cells in a P90 mouse. (B) Tumor cells in the small lesion are GFP+, suggesting that p53 loss is critical for malignant transformation. (C) Co-staining of GFP with proliferation or differentiation markers allows us to perform detailed analysis of tumor organization. Top panels show many actively dividing tumor cells that are Ki67+ GFP+ (inset is a zoomed-in image showing clear GFP/Ki67 overlap). Bottom panels show NeuN+ GFP+ cells within the tumor mass, suggesting that some tumor cells differentiate into neurons (inset is a zoomed-in image showing clear GFP/NeuN overlap).