S100A4 and medulloblastoma: Overexpression of several of the S100 proteins is thought to be involved in tumour progression, such as S100A4, which is upregulated in many cancers including medulloblastoma and promotes angiogenesis and metastasis (Hernan et al, 2003; Emberley et al, 2004; Helfman et al, 2005; Garrett et al, 2006) and S100P which is associated with metastasis in breast and pancreatic cancer (Arumugam et al, 2005; Wang et al, 2006).